When are personnel working in impermeable chemical-protective clothing the most vulnerable to hypothermia?

Personnel working in impermeable chemical-protective clothing are most vulnerable to hypothermia during the decontamination process due to a combination of factors related to heat loss and the nature of their protective gear.

When individuals are engaged in decontamination, they often exert themselves physically, which can lead to sweating. This moisture becomes trapped inside the impermeable clothing because such garments do not allow for breathability. As a result, even though the body is generating heat through activity, the built-up moisture can lead to a significant drop in body temperature as it evaporates, especially if the external environment is cooler or breezy.

Furthermore, decontamination often involves the use of water or chemicals, which can further chill the body when the skin is wet, exacerbating the risk of hypothermia. The combination of physical exertion, trapped moisture, and exposure to cooler conditions creates a scenario where personnel can quickly lose body heat, leading to hypothermia.