Final answer:
Soldiers in MOPP 4 gear can lose roughly 180 g or 7 oz of water per hour through perspiration, assuming low relative air humidity, with significant evaporation also occurring through respiration.
Step-by-step explanation:
When soldiers are in MOPP 4 gear, the highest level of military personal protective equipment, they may be at risk for increased water loss due to perspiration. Discussing the amount of water lost through perspiration, it is considered reasonable to estimate the rate of evaporation at about 3 g/min, which would equate to roughly 180 g or 7 oz per hour. This calculation assumes that the relative humidity of the surrounding air is low, allowing for efficient sweat evaporation. If the air is very dry, this perspiration may evaporate so efficiently that it would not even be noticeable on the skin. However, a significant amount of moisture loss also occurs through respiration - the lungs and breathing passages.