Continuous versus Episodic Hydration in Encapsulating Protective Coveralls

Abstract

Work in warm environments while wearing respiratory protective masks can result in progressive dehydration. The purpose of this study was to evaluate the use of a portable hands-free, through-the-gas mask hydration system on workers in encapsulating protective coveralls (EPC) in the heat. Ten participants performed four trials of simulated “moderate” intensity industrial work (300 Kcal/min) at a wet bulb glove temperature WBGT of 23°C while wearing impermeable (two trials) and semipermeable (two trials) EPC. Participants performed the trials under two conditions: (1) drinking ad libitum from a portable hands-free system (PHFS) using a through-the-gas mask drinking device, and (2) using typical rest-only, wherein participants worked until a termination criterion was met, then were removed from the work environment and permitted to drink as much as they desired. When using the PHFS, for the impermeable EPC trial, participants drank 242% of what they drank during the drinking-during-rest trial. Total work times were unchanged between trials for either condition, but there was a trend for walk time to be longer in PHFS for semipermeable EPC. Dehydration with PHFS was only 21% (dehydration was 4.7 times greater without the PHFS) in impermeable EPC and in semipermeable EPC only 41% of that without hydration available (dehydration was 2.5 times greater without the PHFS). Under these conditions, hypohydration was effectively mitigated using the portable system.

Keywords:

• first responder clothing
• fluid ingestion technique
• heat tolerance
• protective clothing
• work performance

Notes

^A No water was ingested during semipermeable NO trials.