Which condition is a sign of serious heat stress?

Confusion and disorientation are indicative of serious heat stress and can signal that the body is struggling to maintain its normal functioning under extreme heat conditions. When the body overheats, the brain may not receive enough blood or may not function properly due to increased body temperatures, leading to cognitive impairments. This can manifest as confusion, disorientation, or even loss of consciousness, which are critical symptoms that require immediate attention.

The other conditions, while they may show some level of heat-related issues, do not necessarily suggest a serious heat stress scenario. Heavy sweating, for instance, is a common physiological response to heat as the body attempts to cool itself down. Drowsiness may occur but is less severe than confusion or disorientation and does not specifically indicate a critical situation. Reduced appetite may occur in some individuals during extreme heat but is generally not a direct sign of heat stress severity.