How common is dizziness in heat exhaustion?

In heat, sweating helps the body release warmth. Losing fluid can reduce circulating volume, while heat causes blood vessels near the skin to widen. Together, these changes may leave you lightheaded, weak, nauseated, headachy, or unsteady, especially after exertion or standing up.

Heat exhaustion can occur outdoors, in a hot room, or during exercise. Dizziness in a hot setting deserves attention, but it does not by itself prove that heat exhaustion is the cause. Medicines, illness, dehydration, and other problems can also produce similar sensations.

Stop activity and move to a cool, shaded, or air-conditioned place. Lie down with your legs supported if you feel faint, loosen extra clothing, and cool the skin with wet cloths or a fan. Sip cool water or an oral rehydration drink if you are awake, able to swallow, and not vomiting.

Avoid returning to strenuous activity until you feel fully recovered. If symptoms do not improve after cooling and fluids, contact a healthcare professional. Older adults, young children, pregnant people, and those with chronic illness may need advice sooner.

Call emergency services for confusion, collapse, seizures, loss of consciousness, very hot skin, severe worsening symptoms, or difficulty swallowing. These signs can indicate a dangerous heat illness and require immediate assessment.

Seek prompt medical advice for persistent vomiting, worsening weakness, reduced alertness, or dizziness that continues after moving to a cool place and drinking. Do not leave a severely unwell person alone.

Could heat, dehydration, a medicine, or another illness explain my dizziness? How should I replace fluids during hot weather? When can I safely return to exercise, work outdoors, or travel in heat?