Maintenance of core temperature in SCUBA divers in cold water: contributions of anthropometrics, suit type, and sex

Maintenance of core temperature (Tc) is vital for health and physiological function while SCUBA diving in cold water, but there is little research investigating the influence of anthropometrics, suit type, and sex on the rate of change in Tc during real-world diving conditions. We measured the rate of change in Tc (telemetric pill) and thermal sensation (Ts; Young questionnaire) in 62 participants (32 female) before and after non-decompression SCUBA dives using open circuit apparatus breathing air at varied depths and durations in cold water (~ 10 °C). Twenty-three participants wore drysuits (11F), and 39 participants wore wetsuits (21F). There was a significant effect of suit type on the rate of change in Tc, with those in wetsuits having a greater decrease in Tc than those in drysuits. However, there was no effect of suit type on the rate of change in Ts. In wetsuit and drysuit groups, there were significant associations between Tc/min and BSA/BM, BMI, and BM. Estimated body fat % (BF%) was significantly associated with the rate of change in Tc in the wetsuit group only. When separated by sex, there were significant associations with all the anthropometric variables and the rate of change in Tc in the female participants, but only with BM in the wetsuit males. These results suggest that drysuits offer greater thermal protection compared to wetsuits in 10 °C water, and anthropometrics should be considered when selecting the degree of thermal protection, especially for female divers.