At what percent body weight loss is thermoregulation compromised due to hypohydration?

At what percent body weight loss is thermoregulation compromised due to hypohydration?

• A. >3%
• B. >5%
• C. >1%
• D. >10%

Answer: (C)

Small amounts of dehydration already strain the body's cooling system. When body water loss begins, plasma volume falls, which reduces sweating capacity and skin blood flow. That makes it harder to dissipate heat, so thermoregulation starts to be compromised once dehydration passes about 1% of body weight. As dehydration increases to several percent, the cooling system becomes progressively less effective, increasing heat stress and risk. The larger percentages describe more severe dehydration with greater impairment, but the initial compromise occurs near that 1% threshold.

Small amounts of dehydration already strain the body's cooling system. When body water loss begins, plasma volume falls, which reduces sweating capacity and skin blood flow. That makes it harder to dissipate heat, so thermoregulation starts to be compromised once dehydration passes about 1% of body weight. As dehydration increases to several percent, the cooling system becomes progressively less effective, increasing heat stress and risk. The larger percentages describe more severe dehydration with greater impairment, but the initial compromise occurs near that 1% threshold.