Why Heat Exhaustion Can Cause Dizziness

Heat makes blood vessels near the skin widen to release heat. At the same time, sweating removes fluid. Together, these changes can make a person feel lightheaded, unsteady, weak, or close to fainting, particularly after standing up quickly. Dizziness is a common presentation of Heat Exhaustion.

Dizziness is a broad symptom and can come from inner-ear conditions, low blood sugar, infection, heart rhythm problems, medicines, or anxiety. Heat exposure and associated sweating provide useful context, but they do not identify the cause on their own.

Stop the activity and sit or lie down in a cool place. If you feel faint, lie flat and raise your legs if this is comfortable. Loosen excess clothing and use cool air or a cool damp cloth on the skin. Drink small sips of fluid only when you are alert and not nauseated or vomiting.

Rise slowly once the dizziness improves. Do not drive, climb, operate equipment, or return to heat exposure while balance is affected. Arrange for someone to stay nearby if symptoms are significant.

Call for urgent medical help for confusion, fainting, seizure, chest pain, severe headache, trouble breathing, one-sided weakness, difficulty speaking, or persistent vomiting. Seek medical advice if dizziness does not improve with cooling and rest, returns repeatedly, or occurs without a clear heat trigger.

Tell a clinician whether the sensation felt like spinning, lightheadedness, or near-fainting. Include heat exposure, activity, food and fluid intake, medicines, heart symptoms, headache, hearing changes, and any loss of consciousness.