Expired air volumes of males and females during cold water immersion.

Expired air volumes were measured from a random population of adult male and female human volunteers before and during short-term immersion in either cold (13.53 +/- 0.13 degrees C) or warm (33.18 +/- 0.11 degrees C) water. A statistically significant difference was found in the pulmonary ventilation over the first 4 min of immersion between males and females when immersed in cold water. The swim suits worn could not account for the differences observed. No statistically significant difference in pulmonary ventilation was found between males and females during warm water immersion. A numerically smaller group of volunteers was preheated in a sauna before immersion in cold or warm water and this resulted in an attenuated ventilatory response. In this instance there is no statistically significant difference in ventilation between males and females. Also, in another small group of volunteers, surface and deep skin temperatures were continuously measured before and during immersion in cold water. The rates of change of deep skin temperature between males and females were found to be similar.