ABSTRACT
The response of the body to heat stress is called heat strain, and as people are homeotherms, any increase in their core temperature will be an indication of heat strain. There are areas of the body that can be regarded as “core,” and it is the tendency for their temperature to rise, if no action was taken, that defines heat stress. Internal body temperature, skin temperature, heart rate, and sweat rate are the four main physiological measures of heat strain. Internal body temperature is controlled by thermoregulation, so if it is rising above a “set point” equilibrium position, then there is heat gain that can lead to confusion, heat injury, and death. When the body is under heat stress, vasodilation increases skin temperature towards “core” temperature and the skin temperature across the body becomes homogeneous. Heart rate is measured in beats per minute. Management systems are required to ensure health and safety when people are exposed to heat stress.
