Breath-hold times in air compared to breath-hold times during cold water immersions.
Given the effects of cold water immersion on breath-hold (BH) capabilities, a practical training exercise was developed for military/paramilitary personnel completing a helicopter underwater egress training (HUET) program. The exercise was designed to provide firsth and experience of the effects of cold water exposure on BH time. After completing the required HUET, 47 subjects completed two BH testing sessions as well as a short questionnaire. The first BH was completed while standing on the pool deck. The second BH was completed while fully immersed (face down) in 2-3°C water. There were 40 of the volunteers who also breathed from an emergency breathing system (EBS) while in the cold water. Results demonstrated that BH capabilities in cold water were significantly lower than those in ambient air. A significant correlation was also found between BH in air and the difference in cold water vs. air BH capabilities, which suggests that subjects who can hold their breath the longest in air experienced the greatest decrease in BH when immersed. Results indicate that 92% of the subjects reported that the practical cold water immersion exercise had a high value. Finally, 58% of those who used the EBS reported that it was harder to breathe in cold water than while in the training pool (approximately 22°C). The BH times for this group were similar to those reported in previous cold water immersion studies. Based on the questionnaire results, it is possible, when carefully applied, to include a practical cold water immersion exercise into existing HUET programs.