Which of the following is an indicator of heat-related illness?

Flushed skin is indeed an indicator of heat-related illness. When the body is exposed to high temperatures, it attempts to cool down through various mechanisms, including increased blood flow to the skin, which can result in a flushed or reddened appearance. This response is part of the body’s attempt to dissipate heat through radiation and convection.

While cold extremities are often associated with other medical conditions such as shock or hypothermia, nausea and vomiting can occur in both heat-related illnesses and different medical situations but are more indicative of advanced heat stress. Excessive sweating, though it can signal the body’s effort to cool itself, is often expected during heat exposure and does not necessarily indicate an illness on its own. Therefore, flushed skin stands out as a more direct indicator of the physiological changes that occur specifically due to heat-related illness.