Does heat exhaustion cause nausea?

In hot conditions, blood flow is directed toward the skin to release heat, while sweating removes fluid and salts. This combination can affect the digestive system and cause nausea, reduced appetite, weakness, dizziness or headache. Nausea can also come from infection, food-related illness or medicines, so it does not by itself identify heat exhaustion.

End the activity and move into shade or air conditioning. Sit or lie down, loosen clothing and cool the skin. If you are awake and can swallow, take tiny, frequent sips of cool water or an oral rehydration drink rather than drinking quickly. Avoid alcohol and heavy meals while nauseated. Do not force fluids if vomiting or if alertness is reduced.

Get urgent medical help if vomiting prevents drinking, or if confusion, fainting, seizure, very hot skin or worsening weakness develops. Seek assessment when symptoms fail to improve after cooling and rest, or when nausea is severe or recurrent. A person with reduced alertness should be monitored and not left alone.

Ask whether fluid replacement is suitable for you, how to return to activity, and whether another cause should be checked if nausea continues.