Reply to “Hypothermia in Open-Water Swimming Events: A Medical Risk That Deserves More Attention”

To the Editor:

We thank Castro and Nobrega for their interest in our article. Their paper ¹ published shortly after ours ² serves to further highlight the potential for the development of hypothermia during endurance open-water swimming. Although they studied a smaller, elite athlete group, the race conditions were similar to those we encountered. Their reported hypothermia rate of 83% (10 of 12 subjects) is very high but is likely, at least to some extent, to be explained by their use of infrared emission detection tympanic thermometers. Our experience ³ and that of others ⁴ is that these devices overestimate the incidence of hypothermia and are not a suitable tool for screening for hypothermia in swimmers. We concur with them that “hypothermia is a great potential medical risk during open-water swimming events” and that “more studies evaluating preventive measures are therefore warranted.” The caveat we would add is that such studies will need to carefully consider the method of temperature measurement chosen.