Which statement is true about heat stress?

The statement about lack of sweat being a symptom of heat stroke is accurate because heat stroke typically occurs when the body becomes overwhelmed by heat and is unable to regulate its temperature. One of the critical features of heat stroke is the failure of the body to cool itself through sweating, which can lead to a rapid increase in body temperature and potentially fatal consequences.

On the other hand, the other statements contain inaccuracies. Heat stress can affect individuals in a variety of environments, not just those working outdoors, as high temperatures can also be encountered indoors, particularly in poorly ventilated spaces. While drinking cold water is an important part of staying hydrated in hot conditions, it is not always sufficient on its own to prevent heat stress, as other measures such as acclimatization to heat, taking breaks, and utilizing shade or cooling techniques are also important. Lastly, heat stress can lead to severe health consequences if not addressed, including heat exhaustion and heat stroke, both of which require immediate medical attention.