When to worry about nausea with heat exhaustion

Heat exhaustion develops when heat, sweating, and exertion lead to loss of body fluid and salt. Nausea may occur with heavy sweating, headache, dizziness, weakness, muscle cramps, thirst, or cool clammy skin. The priority is to stop heat exposure and cool the person; symptoms can become dangerous if the body can no longer regulate temperature.

Move to a cool shaded or air-conditioned place, loosen unnecessary clothing, and cool the skin with wet cloths, fanning, or a cool shower. If the person is awake and able to swallow, give frequent small sips of cool water or an oral rehydration drink. Stop exercise and stay with them while watching alertness, breathing, and ability to drink.

Call emergency services if the person becomes confused, faints, has a seizure, cannot drink, has trouble breathing, develops very hot skin, or is difficult to wake. Do not give drinks to someone who is drowsy or unable to swallow. Seek medical assessment if nausea, dizziness, weakness, or vomiting does not improve promptly after cooling and fluids, or returns when activity resumes.

Ask how to return safely to activity, whether medicines or an illness increase heat risk, what fluids suit you, and which early symptoms should prompt you to stop working or exercising.