What is the core feature of heat stress?

The core feature of heat stress is high core temperature. When the body is exposed to high environmental temperatures, it struggles to maintain its normal temperature through various mechanisms like sweating and vasodilation. Heat stress occurs when the body can no longer effectively dissipate heat, leading to an elevation in the core body temperature. This rise can result in physiological disturbances and may progress to more severe conditions like heat exhaustion or heat stroke if not managed promptly.

While low blood pressure, increased respiration rate, and loss of consciousness can all be associated with heat stress, they are not the defining characteristic. Instead, they may be symptoms or consequences of the body’s inability to regulate its core temperature. For example, increased respiration rate can occur as the body attempts to cool itself through evaporative cooling, but it is the elevated core temperature that is the direct indicator of heat stress.