Abstract
Heat stress in high-temperature environments is a major concern for public health and animal welfare. However, cooling materials used in commercial companion animal apparel are often adopted from human apparel without independent scientific validation. This study compared the contact cooling performance of fabrics used in canine and human apparel based on the same physical performance index, Q-max, to examine the validity and limitations of applying this human-centered index to canine cooling garment design. Q-max was measured in accordance with JIS L 1927 (ΔT = 10 °C) for 24 commercially available cooling fabrics each for canine and human apparel under identical testing conditions. The relationships of fabric thickness, weight, air permeability, and material composition with Q-max were also statistically analyzed. Although the two groups showed similar mean Q-max values, they differed in distribution range and variability. Fabrics for canine apparel exhibited greater variance and a broader maximum range of Q-max values, and substantial variation was observed even within identical material compositions. Some canine apparel fabrics showed Q-max values equivalent to or higher than those of human apparel fabrics, confirming that contact cooling performance is not determined solely by end-use classification. Thickness, weight, and air permeability did not show consistent linear relationships with Q-max, suggesting that contact cooling performance is shaped by complex interactions between material composition and fabric structure rather than by a single factor. Because Q-max represents intrinsic contact heat transfer under direct-contact conditions, its application to canine apparel should be interpreted cautiously when fur alters the fabric–skin interface. These findings support a multi-property approach to the design and evaluation of canine cooling garments.
1. Introduction
Increasing exposure to high-temperature environments has raised concerns regarding heat-related illness in both humans and companion animals. Dogs are particularly vulnerable because they have limited capacity for whole-body sweating and rely primarily on panting and localized heat exchange for thermoregulation.1–3 Their thermal responses may also vary according to activity, body size, age, breed, body condition, coat characteristics, and seasonal conditions.4–8 In addition, coat type and body region influence surface-temperature patterns and heat dissipation.9–11 These characteristics highlight the need for cooling strategies that reflect canine thermophysiology. However, cooling materials used in commercial canine apparel are frequently selected within design contexts established for human apparel, while quantitative evidence supporting their suitability for canine use remains limited.
In human apparel research, immediate contact cooling is commonly evaluated using maximum heat flux (Q-max), which represents the peak transient heat transfer occurring when a fabric first contacts a warmer surface.12–15 However, thermophysiological comfort is a multidimensional property governed by the combined effects of fiber and yarn characteristics, fabric construction, thickness, mass, porosity, layering, and heat and moisture transport. Previous studies have shown that yarn parameters and fabric geometry can affect thermal resistance, thermal conductivity, thermal absorptivity, air permeability, and water-vapor transfer, while combinations of inner and outer fabric layers can further modify overall thermal behavior.16–20 Clothing configuration and interfacial air layers also influence heat-transfer pathways.21–23 These findings indicate that cooling performance cannot be inferred solely from fiber composition or a single macroscopic structural parameter.
Although Q-max provides a standardized basis for comparing intrinsic contact heat-transfer performance, it has been developed and interpreted primarily under direct fabric–skin contact conditions in human apparel. In dogs, the fur-covered body surface may reduce effective fabric–skin contact and introduce an additional interfacial air layer. Consequently, identical Q-max values measured at the fabric level may not produce equivalent cooling effects under actual canine wear conditions. Despite this fundamental difference, few studies have directly compared fabrics used in canine and human cooling apparel under identical standardized conditions or examined how their Q-max distributions relate to basic material and structural properties.
Accordingly, this study compared the Q-max values of 24 commercially available cooling fabrics used in canine apparel and 24 used in human apparel under identical JIS L 1927 testing conditions. The relationships between Q-max and fabric thickness, weight, air permeability, and fiber composition were also examined. The study was deliberately limited to intrinsic fabric-level properties rather than species-specific wear simulation. Its objectives were to characterize the Q-max distributions of the two fabric groups, identify material and structural factors associated with Q-max variability, and clarify the appropriate scope and limitations of applying this human-centered index to canine cooling-apparel evaluation.
2. Methods
2.1. Samples
A total of 48 cooling functional fabrics (24 for canine apparel and 24 for human apparel) within comparable product categories were selected to comparatively analyze their contact cooling sensation characteristics under identical conditions. Only fabrics used in commercially available products intended for summer wear were chosen, and were included in the study only when the product specifications or manufacturer descriptions explicitly indicated cooling functionality. The fabrics for canine apparel were obtained from commercially available cooling garments for dogs. The human fabrics consisted of textiles with cooling functionality and intended for direct skin contact, such as those used in sportswear and innerwear.
Fiber composition, knitted structure, thickness, and weight of the cooling fabrics used in this study.
Note. D denotes canine cooling fabrics, and H denotes human cooling fabrics.
The distinction between fabrics for canine apparel and those for human apparel in this study does not constitute a strict materials-science classification based on fiber properties; rather, it represents an experimental categorization reflecting the design and end-use contexts in which the fabrics are used in the actual market. Therefore, the two groups should be understood not as fundamentally different material classes, but as comparative groups used to compare and explore the material-property distribution characteristics of the fabrics selected and utilized within different product design environments. The purpose of this study is not to determine performance superiority between species-specific fabrics, but to elucidate the distinct distribution patterns and interpretive differences of a common cooling-related material property index (Q-max) when applied to fabric groups in different end-use contexts.
2.2. Measurement of contact cooling sensation (Q-max)
The contact cooling sensation of the fabrics was quantitatively assessed using Q-max, defined as the maximum heat flux at the moment of initial contact between the fabric and the sensor. Previous studies have adopted Q-max as an objective indicator of contact cooling sensation and have also reported its association with subjective cool feeling.12–15
Q-max measurements were commissioned to the accredited testing organization FITI Testing & Research Institute (Republic of Korea) and were conducted in accordance with the JIS L 1927 testing method. All specimens were prepared in a uniform size (50 × 50 cm) in accordance with the specifications indicated by the testing institute and conditioned for at least 24 h prior to testing under ISO 139 conditions (23 ± 1 °C, 65 ± 5% RH).
24
The surface in contact with the sensor (corresponding to the skin-contact side during wear) was kept consistent across all specimens, and a consistent placement direction was ensured for all specimens to account for the possibility that the knit orientation (e.g., wale/course direction) may affect measurement outcomes (Figure 1). Schematic of the experimental workflow for Q-max measurement.
The temperature difference (ΔT) between the sensor and specimen during measurement was set to 10 °C. The ΔT = 10 °C condition has been widely used in studies evaluating contact cooling sensation13–15 and is considered suitable for comparing the initial heat flux characteristics among specimens. The Q-max value of each specimen was measured five times under identical conditions (n = 5), and the mean of the repeated measurements was used as the representative Q-max value. The environmental conditions and test parameters (e.g., sensor temperature, contact pressure, and contact duration) were controlled in accordance with JIS L 1927 and the standard operating procedures of the testing institute.
No artificial fur layer or controlled air gap was introduced because the study was designed to compare the intrinsic contact heat-transfer properties of the fabrics under standardized direct-contact conditions. Accordingly, the measured Q-max values represent fabric-level performance and should not be interpreted as direct measures of cooling performance during actual canine wear.
2.3. Measurement of structural parameters
The thickness, weight, and air permeability of each specimen were measured as auxiliary material-property variables to analyze fabric structural parameters that could affect Q-max. These parameters may influence the air gap formed during fabric–skin (or sensor) contact and the transient heat flux behavior at the initial moment of contact.22,23 All specimens were conditioned for at least 24 h prior to measurement under ISO 139 conditions (23 ± 1 °C, 65 ± 5% RH). 24 Each property measurement was repeated under identical conditions for each specimen, and the arithmetic mean of the repeated measurements was used as the representative value.
2.3.1. Fabric thickness
Fabric thickness was measured using a fabric thickness tester (Ozaki Mfg. Co., Ltd., Tokyo, Japan) in accordance with ISO 5084. 25 The thickness of each specimen was measured three times under identical conditions, and the mean value was used as the representative thickness value.
2.3.2. Fabric weight
Fabric weight was calculated as mass per unit area (g/m2) in accordance with ISO 3801. 26 Each specimen was cut to the specified area, weighed using an electronic balance (XS204, Mettler Toledo, Greifensee, Switzerland), and the mass per unit area was calculated accordingly. Weight is a structural parameter related to the density of the fiber assembly and the thermal mass characteristics of the fabric. Therefore, it was included in the analysis as a factor that may affect Q-max variability.
2.3.3. Air permeability
Air permeability was measured using an air permeability tester (HAN WON SOWAY CO., Seoul, Korea) in accordance with ISO 9237. 27 Tests were conducted under the specified pressure differential, and the air permeability of each specimen was measured three times under identical conditions; the arithmetic mean of the repeated measurements was used as the representative air permeability value.
The measured thickness, weight, and air permeability were used as independent variables, and their relationship with Q-max was analyzed.
2.4. Data analysis
Data were analyzed with a focus on the distribution characteristics of Q-max and its relationship with structural parameters. First, the fabrics were categorized into cooling fabrics for canine apparel (n = 24) and cooling fabrics for human apparel (n = 24), and descriptive statistics for Q-max (mean, median, interquartile range (IQR), minimum–maximum, and the coefficient of variation (CV)) were calculated. The distribution characteristics of the measured properties of the two fabric groups were visualized using boxplots and histograms.
The relationships between Q-max and the fabric structural parameters (thickness, weight, and air permeability) were evaluated using Pearson’s correlation. Correlation coefficients (r) were calculated for all specimens (n = 48), the canine apparel fabric group, and the human apparel fabric group separately to examine the dependence of the relationships between structural parameters and Q-max on the end-use context. In addition, Fisher’s r-to-z transformation was applied to compare differences in correlations between the canine and human apparel fabric groups. Multiple linear regression analysis was also conducted to examine the combined effects of thickness, weight, and air permeability on Q-max, with the three structural parameters entered simultaneously using the enter method.
The statistical analyses conducted in this study were not intended to determine performance superiority through hypothesis testing of mean differences between groups; rather, they were used to quantitatively support and verify the trends observed in interpreting the distribution characteristics of Q-max and its relationships with structural parameters. Statistical significance was employed as a reference index to aid in the interpretation of these trends. All statistical analyses were conducted using IBM SPSS Statistics 28.0 (IBM Corp., Armonk, NY, USA), with the significance level set at p < 0.05.
3. Results and discussion
3.1. Q-max distribution and comparative contact cooling performance of canine and human cooling fabrics
The Q-max distributions of canine (n = 24) and human cooling fabrics (n = 24) were compared under identical testing conditions (JIS L 1927, ΔT = 10 °C). Rather than ranking the two end-use groups, the analysis focused on differences in range, variability, extreme values, and distributional overlap.
Figure 2 presents the boxplots for the two groups, and Table 2 summarizes the descriptive statistics. Q-max ranged from 0.042 to 0.210 W/cm2 for canine fabrics and from 0.056 to 0.180 W/cm2 for human fabrics. Despite these differences in range, the mean values were nearly identical at 0.118 and 0.119 W/cm2, respectively. Boxplot of the Q-max distribution of cooling fabrics for canine apparel (n = 24) and human apparel (n = 24). Descriptive statistics of Q-max values for canine and human cooling fabrics.
The canine fabric group exhibited greater variability than the human fabric group, as indicated by its larger standard deviation, wider overall range, higher maximum value, and higher coefficient of variation (33.49% vs. 27.17%). These results indicate greater heterogeneity in the contact-cooling performance of the sampled canine fabrics. Previous studies have shown that Q-max is influenced by fabric structure, thermal properties, contact conditions, and transient heat-transfer behavior.12,15–17,21–23 The wider variation observed in the canine group may therefore reflect greater diversity in the structural and surface characteristics of the commercial fabrics included in this study.
Although the two groups differed in variability and range, their Q-max distributions overlapped substantially. Some canine fabrics exhibited values comparable to or higher than those of human fabrics, indicating that end-use classification alone does not determine contact-cooling performance. Figure 3 further illustrates the frequency distributions using a common bin width of 0.02 W/cm2. Canine fabrics were distributed across a wider range, including both relatively low and high Q-max values, whereas human fabrics were more concentrated within a narrower interval. Histogram of the Q-max distribution of cooling fabrics for canine apparel (n = 24) and human apparel (n = 24).
The difference in mean Q-max between the two groups was not statistically significant (p > 0.05). Accordingly, the results were interpreted primarily in terms of distributional range, variability, and overlap rather than mean-based group superiority. These findings demonstrate that contact-cooling performance varies considerably within each end-use category and cannot be adequately represented by the group mean alone.
3.2. Influence of material composition and structural parameters on contact cooling performance
Pearson’s correlation coefficients between Q-max and structural parameters (overall and by fabric-use group).
Scatter plots of Q-max versus (a) thickness, (b) weight, and (c) air permeability.
3.2.1. Thickness and Q-max
For all specimens, the correlation coefficient between the thickness and Q-max was r = −0.083 and was not statistically significant (p = 0.575; Table 3). No significant linear correlation between thickness and Q-max was observed for the canine (r = −0.199, p = 0.352) and human (r = 0.038, p = 0.861) apparel fabric groups when analyzed separately.
As shown in the scatter plots in Figure 4(a), the Q-max values are widely distributed across the full range of thickness for both fabric groups, and no clear dependence of Q-max on the thickness is evident. These results do not support the simple assumption that thinner fabrics necessarily produce a greater contact cooling sensation under the present experimental conditions. In other words, thickness does not solely govern contact cooling performance, but may indirectly affect Q-max through interactions with material composition, surface properties, and the internal pore structure of the fabric.
3.2.2. Weight and Q-max
For all specimens, the correlation coefficient between weight and Q-max was r = −0.154, and it was not statistically significant (p = 0.296; Table 3). Similarly, low correlation coefficients were observed for the canine (r = −0.239, p = 0.260) and human (r = −0.017, p = 0.936) apparel fabric groups, indicating no clear linear relationship between weight and Q-max.
As shown in Figure 4(b), Q-max values vary widely even within the same weight range, and the dependence of Q-max on weight is not evident. Although weight is a structural parameter related to the thermal mass and fiber density of the fabric, these results suggest that heat transfer at the moment of contact may be influenced more by factors such as microscopic contact area, surface roughness, and fiber arrangement than by fabric weight alone.
3.2.3. Air permeability and Q-max
For all specimens, the correlation coefficient between air permeability and Q-max was r = −0.042 (p = 0.777). No statistically significant linear correlation was observed for the canine (r = −0.181, p = 0.397) and human (r = 0.016, p = 0.942) apparel fabric groups (Table 3).
As shown in the scatter plots in Figure 4(c), even though air permeability spans a wide range, the Q-max values are distributed within a comparatively narrow range relative to the variation in air permeability, and no clear dependence of Q-max on air permeability is observed. This can be explained by the fact that air permeability is primarily related to long-term heat and moisture exchange and overall comfort during wear, whereas Q-max reflects the heat-transfer characteristics at the initial moment of contact between the fabric and skin. Therefore, although air permeability is an important indicator for evaluating wear comfort, it is limited as a single predictor of contact cooling performance.
3.2.4. Effect of fiber composition on Q-max distribution
The Q-max distribution characteristics according to material composition were distinct for the polyester 100%, polyester/spandex, and nylon/spandex groups. The Q-max values for polyester 100% fabrics tended to be concentrated within a relatively narrow range, regardless of whether they were intended for canine or human use, whereas those for nylon/spandex blended fabrics showed a wide distribution ranging from low to very high.
In particular, for nylon/spandex blended fabrics, a wide variation in Q-max values was observed even within the same material composition. This suggests that contact cooling performance is more sensitive to factors such as knitting or weave structure, yarn thickness, surface microtopography, and actual contact conditions, rather than to the material composition itself. Therefore, although material composition can affect contact cooling performance, the Q-max levels cannot be determined solely from a single compositional factor.
3.2.5. Comparison between canine and human fabric groups
Comparison of correlation coefficients between canine and human cooling fabric groups using Fisher’s r-to-z transformation.
Thus, even for the same structural parameters, the relationships between Q-max and these parameters are not fundamentally different between the canine and human apparel fabric groups. These results suggest that contact cooling performance depends on complex physical and structural characteristics of the fabric rather than the target user. These findings also support, from a structural perspective, the partial overlap in Q-max distributions between the two groups observed in Section 3.1.
3.2.6. Integrated interpretation of structural relationships
Overall, the correlation analyses indicate that Q-max cannot be explained by any single macroscopic structural parameter examined in this study. Thickness, weight, and air permeability showed weak and nonsignificant linear relationships with Q-max in both the canine and human fabric groups. In addition, Fisher’s r-to-z comparisons showed that the strengths of these relationships did not differ significantly between the two end-use groups.
A multiple linear regression analysis was also conducted to examine the combined explanatory effects of thickness, weight, and air permeability. The model explained 4.5% of the variance in Q-max (R2 = 0.045, adjusted R2 = −0.020, F(3, 44) = 0.697, p = 0.559). Thickness (β = 0.337, p = 0.344), weight (β = −0.461, p = 0.199), and air permeability (β = −0.059, p = 0.694) were not significant predictors of Q-max. These results indicate that the measured macroscopic structural parameters, even when considered simultaneously, provided limited explanatory power for Q-max variability.
From a heat-transfer perspective, Q-max represents the peak transient heat flux generated immediately after contact between surfaces at different temperatures. Its magnitude is therefore influenced not only by the bulk dimensions of the fabric but also by the thermal properties of the constituent fibers, the effective solid-to-solid contact area, and the thermal resistance at the fabric–sensor interface. A larger effective contact area and lower interfacial resistance may promote rapid initial heat transfer, whereas surface irregularities, internal pores, and trapped air may reduce direct contact and impede heat flow.
These mechanisms help explain why thickness and weight did not show consistent linear relationships with Q-max. Although fabric thickness is generally associated with through-thickness thermal resistance, Q-max is measured during the initial moment of contact and may be particularly sensitive to the structure of the contact surface. Similarly, fabric weight represents the quantity of material per unit area, but fabrics with comparable weights may differ in yarn geometry, knit density, loop configuration, porosity, compressibility, and surface topography. Consequently, similar thickness or weight values do not necessarily produce equivalent contact areas or interfacial heat-transfer conditions.
For example, finer yarns and greater knit density may increase the number of potential contact points and produce a more continuous heat-transfer pathway at the fabric surface. Conversely, coarse yarns, open loop structures, and pronounced surface irregularities may reduce the effective contact area and retain more air at the interface, thereby increasing contact thermal resistance. However, because yarn fineness and knit density were not directly measured in this study, these relationships should be regarded as mechanistic interpretations requiring experimental verification.
The weak relationship between air permeability and Q-max may reflect the different heat-transfer phenomena represented by these properties. Air permeability characterizes airflow through interconnected pores under an applied pressure difference and is primarily relevant to convective heat and moisture exchange. In contrast, Q-max mainly reflects the short-duration transfer of heat through solid contact regions and the intervening air at the interface. Therefore, a fabric with high air permeability does not necessarily exhibit a high Q-max value.
The wide variation in Q-max observed within the same fiber-composition categories further indicates that fiber composition alone does not determine contact cooling performance. Characteristics not directly measured in this study, including yarn fineness, filament arrangement, knit density, loop geometry, surface topography, finishing treatments, and effective contact area, may alter the transient heat-transfer pathway and contribute to Q-max variability. Because these microstructural characteristics were not directly quantified, their effects cannot be confirmed from the present data and should be regarded as plausible mechanisms requiring further investigation. Accordingly, the structural variables evaluated in this study should be interpreted as complementary descriptors rather than independent predictors of contact cooling performance.
3.3. Implications for designing cooling fabrics for canine apparel considering canine thermophysiology
This section provides an integrated interpretation of the Q-max distribution characteristics described in Section 3.1 and the limited correlations with structural parameters described in Section 3.2 from the perspective of canine thermophysiology. It also discusses the limitations of directly applying human contact-cooling design concepts to canine apparel.
Humans and dogs exhibit fundamental differences in thermoregulation mechanisms. In humans, evaporative heat loss via sweat glands distributed across the body is the primary means of temperature regulation. In contrast, dogs have limited sweat gland functionality and rely primarily on panting and localized heat dissipation through specific regions, such as the ears, abdomen, and trunk. These differences indicate that heat-transfer pathways and cooling perception when wearing cooling garments are not the same between the two species, suggesting that design concepts effective for human cooling apparel may not be similarly effective for canine apparel.
The performance index Q-max used in this study quantifies the maximum heat flux at the initial moment of contact between the fabric and skin and is a useful material-property indicator of the immediate cooling sensation perceived in humans. However, in dogs, the presence of a fur layer likely creates an air gap between the fabric and skin; therefore, Q-max values measured under laboratory conditions may not translate directly into equivalent cooling effects during actual wear. That is, in the canine wear environment, additional thermal resistance (e.g., the fur-induced air gap) may limit how effectively the instantaneous heat transfer indicated by Q-max contributes to actual body heat dissipation.
This interpretation is closely linked to the Q-max distribution observed in this study. Although some cooling fabrics for canine apparel exhibited very high Q-max values, the variation in the range of Q-max values was considerably high, even within the same nylon/spandex blend group. In contrast, polyester 100% fabrics exhibited a relatively narrow Q-max range, indicating stable but limited contact cooling performance. These results suggest that, beyond achieving high Q-max values, the structural, surface, and contact conditions leading to high Q-max values may be more critical design variables in actual wear environments.
Figure 5 schematically illustrates the body heat-transfer pathways in dogs wearing cooling garments. In particular, it highlights how the fur layer may create an air gap that limits fabric–skin contact and reduces the practical cooling effect implied by laboratory-measured Q-max values. Schematic of heat-transfer pathways in cooling garments.
To better approximate canine wear conditions, future studies could employ a controlled fabric–fur–skin interface model. Artificial fur layers with systematically varied thickness, fiber length, and density could be positioned between the cooling fabric and a heated skin-simulating surface. In addition, spacer frames or adjustable supports could be used to establish defined air-gap distances, while contact pressure and fabric tension are maintained under controlled conditions. Such experiments should assess not only the initial peak heat flux represented by Q-max, but also time-dependent heat-flux changes, cumulative heat transfer, and surface-temperature responses. This approach would help determine how fabric-level Q-max values are modified by fur and air-gap conditions during simulated canine wear.
The correlation analysis results (Table 3 and Figure 4) indicated that Q-max is not linearly correlated with individual structural parameters, such as thickness, weight, or air permeability. Moreover, Fisher’s r-to-z transformation results (Table 4) indicated no statistically significant difference in correlations between the canine and human apparel fabric groups. These results suggest that contact cooling performance is not determined by a single structural parameter or target group but rather emerges from the interaction among multiple material properties and contact conditions.
Accordingly, Q-max should be incorporated into a combined evaluation framework rather than used as a stand-alone criterion for canine cooling design. Q-max can characterize the initial contact-cooling response, while thermal conductivity or thermal resistance, time-dependent heat-flux decay, and cumulative heat transfer can provide information on sustained heat dissipation. Air permeability, water-vapor transfer, moisture-wicking behavior, and drying rate may additionally reflect heat and moisture management during prolonged wear. For canine applications, these material-level indices should be evaluated together with interface-related factors, including fur characteristics, air-gap distance, contact pressure, and body region. Such a multidimensional approach would distinguish immediate contact cooling from sustained thermal management and provide a more appropriate basis for evaluating canine cooling garments.
For practical application, these considerations can be organized into a provisional stepwise decision framework for canine cooling-garment design. First, candidate fabrics should be screened using Q-max to compare their initial contact-cooling response within the intended product category. Second, fabrics should be evaluated using complementary properties related to sustained heat and moisture management, including thermal resistance or conductivity, air permeability, water-vapor transfer, wicking, and drying behavior. Third, the shortlisted fabrics should be assessed under controlled fabric–fur–skin interface conditions that reflect coat characteristics, air-gap distance, contact pressure, garment fit, and target body region. Finally, garment prototypes should be validated using time-dependent heat flux and surface-temperature responses before design recommendations are extended to actual canine wear. Because the present study did not relate Q-max to physiological responses or garment-level cooling outcomes, a universal numerical Q-max threshold cannot be established from the current data. The proposed framework should therefore be regarded as a decision sequence for material screening and validation rather than as a fixed pass–fail standard.
A further limitation concerns the selection of commercially available cooling fabrics. Eligibility was based on product specifications or manufacturer descriptions indicating cooling functionality, and the sample set was purposively balanced across three fiber-composition categories rather than randomly or proportionally sampled from the market. This approach supported controlled comparison between the canine and human fabric groups but may have over- or underrepresented particular constructions relative to their actual commercial prevalence. Reliance on product descriptions may also introduce classification bias because detailed information on yarn characteristics, knit density, surface geometry, finishing treatments, and proprietary cooling technologies was not consistently available. Accordingly, the investigated samples do not encompass the full range of commercial or engineered cooling-material systems, and the findings should be interpreted as representing the Q-max distributions and structural relationships observed within this specific sample set rather than as being universally generalizable to all canine or human cooling fabrics. Future studies should use broader and more systematically documented sample sets, including controlled fabric constructions, yarn parameters, surface structures, functional finishes, and engineered material configurations.
4. Conclusion
In this study, cooling fabrics for canine and human apparel were compared under identical test conditions (JIS L 1927, ΔT = 10 °C). The distribution characteristics of Q-max, a contact cooling sensation index, and their relationships with selected structural parameters were evaluated at the material-property level. The primary objective was not simply to determine which fabric group showed superior cooling performance, but to examine how a cooling index established for human apparel is distributed in canine apparel fabrics and to clarify the limitations of its interpretation.
The analysis revealed that cooling fabrics for canine and human apparel exhibited similar mean Q-max values but distinct distribution ranges and variability. In particular, within the canine apparel fabric group, a wider variance and broader maximum range of Q-max values were observed, and substantial deviations in contact cooling performance were observed, even within identical material compositions. These findings indicate that cooling performance is not determined solely by the intended use of the fabric and that both fabric groups exhibit a broad spectrum of performance.
Analysis of the relationship between Q-max and structural parameters showed that individual variables, such as thickness, weight, and air permeability, did not exhibit consistent linear relationships with Q-max. This suggests that contact cooling performance is not governed by a single structural factor but is a complex characteristic resulting from the interactive effects among material composition, fabric structure, surface properties, and contact conditions. Nylon/spandex blended fabrics exhibited a wide variation in Q-max values even within the same composition, whereas polyester 100% fabrics exhibited a relatively narrow variation. These results indicate that although specific material compositions may provide the potential range of cooling performance, the actual realized performance depends predominantly on the overall design.
Taken together, the findings indicate that Q-max is useful for standardized screening of the intrinsic contact-cooling response of fabrics used in canine apparel, but it should not be interpreted as a direct measure of garment-level cooling or heat-stress mitigation. Because the canine fabric–skin interface is modified by fur and contact conditions, material-selection decisions should integrate Q-max with indices of sustained heat transfer, moisture management, and fabric–fur–skin interface conditions. Future studies should validate the relationship between fabric-level Q-max and time-dependent heat transfer under controlled fur and air-gap conditions, while also employing systematically engineered fabric sets with controlled constructions, microstructures, and functional treatments.
Footnotes
Acknowledgements
This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (no. RS-2023-00278093).
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (no. RS-2023-00278093).
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data Availability Statement
The authors confirm that the data supporting the findings of this study are available within the article.