What common symptom might indicate heat stress?

Pale and clammy skin is a common symptom that may indicate heat stress. This condition occurs when the body is unable to cool itself effectively in excessively hot conditions, leading to physiological changes to manage overheating. The skin may become pale and sweaty as the body attempts to regulate temperature through perspiration. This symptom suggests that the body's cooling mechanisms are being overwhelmed, which can be a warning sign of heat-related illnesses, such as heat exhaustion or heat stroke.

The other choices either do not specifically indicate heat stress or do not provide a complete picture of its symptoms. Excessive sweating alone is not enough to confirm heat stress, as it may also occur in other situations. An increased heart rate is a symptom often associated with various conditions, not specifically indicative of heat stress without additional context. Persistent coughing typically relates to respiratory issues rather than temperature regulation. Therefore, recognizing pale and clammy skin as a symptom helps to appropriately identify and respond to potential heat stress in individuals.