How long do heat stroke symptoms last?

Heat stroke affects temperature control and can impair the brain, circulation, kidneys, and other organs. Symptoms may change quickly: headache or nausea can progress to confusion, fainting, seizure, or difficulty waking. Improvement after moving into a cool place does not prove that the danger has passed. Heat exhaustion is a milder heat illness, but the distinction can be difficult when symptoms are developing.

Call emergency services at once, move the person to a cooler place, remove unnecessary clothing, and cool the skin with wet cloths, fanning, or a cool shower when safe. Do not leave the person alone. Give no drink to anyone who is confused, vomiting, having a seizure, or unable to swallow. Clinicians may continue cooling and use IV Fluid Therapy after assessment.

Seek emergency care as soon as heat stroke is suspected, regardless of whether symptoms have lasted briefly or for longer. Persistent headache, weakness, vomiting, confusion, reduced alertness, or a high temperature after cooling needs medical review. Fever after heat exposure can have another cause and should not be used to delay assessment.

Ask which symptoms should be monitored after treatment, when fluids and food are safe, how long to avoid heat and exertion, and whether follow-up tests are needed.