Headache from heat exhaustion: what to know

Headache is a common presentation of heat exhaustion, which can also cause heavy sweating, thirst, dizziness, and weakness. Move to a cool place, stop exertion, loosen clothing, and begin cooling and rehydration promptly. Do not return to heat or activity while symptoms continue.

Sweating in a hot environment removes fluid and salts. As the body loses volume and struggles to regulate temperature, headache may appear with fatigue, nausea, cramps, clammy skin, or light-headedness. Dark urine and intense thirst can support concern about dehydration. Heat exhaustion can worsen into heatstroke, especially when a person becomes confused or stops sweating.

Rest indoors or in shade, apply cool wet cloths, fan the skin, and sip cool water or an oral rehydration drink if you are alert and able to swallow. Avoid alcohol and strenuous activity. Have someone stay with you and reassess after cooling. If symptoms do not improve promptly, arrange urgent medical care rather than trying to push through them.

Call emergency services for confusion, collapse, seizure, loss of consciousness, very hot skin, severe breathing difficulty, or inability to drink. These can indicate heatstroke or another emergency. Also seek prompt care for ongoing vomiting, worsening headache, marked weakness, or symptoms after prolonged heat exposure, particularly in a child, older adult, or person with a chronic illness.

Ask how much recovery time you need, when exercise and heat exposure can resume, whether medicines increase heat risk, and how to plan fluids and breaks for future hot-weather activity.