Which of the following is not a symptom of heat stress?

High blood pressure is not typically considered a symptom of heat stress. Instead, heat stress is characterized by a range of symptoms that occur as the body's temperature regulation mechanisms become overwhelmed. These symptoms include fatigue and exhaustion, dizziness and fainting, as well as headache and nausea.

During heat stress, the body struggles to cool itself effectively, leading to an elevated heart rate, increased perspiration, and potential dehydration. Symptoms that reflect the body's inability to cope with heat primarily manifest in ways that directly relate to heat exposure. While high blood pressure can be influenced by many factors, it is not a direct symptom of heat stress. Thus, recognizing heat stress involves understanding its primary indicators, which center around the body's response to excessive heat rather than chronic conditions like high blood pressure.