When is IV fluid therapy recommended for heat exhaustion?

Heat exhaustion develops when heat, sweating, and exertion cause the body to lose water and salts faster than they are replaced. A clinician assesses temperature, alertness, circulation, breathing, urine output, and response to cooling and oral fluids. A drip may be used when the person remains weak or dizzy, cannot keep fluids down, or needs monitored replacement. Confusion, seizures, loss of consciousness, or very hot skin raise concern for heatstroke, which is an emergency rather than routine heat exhaustion.

Move to a cool place, loosen extra clothing, rest, and cool the skin with water, airflow, or cool packs wrapped in cloth. If fully alert and able to swallow, give small sips of water or an oral rehydration drink. Stop exertion and avoid alcohol. Do not give anything by mouth to someone who is confused, unconscious, or vomiting repeatedly; call emergency services instead.

Get emergency help for confusion, collapse, seizure, loss of consciousness, severe breathlessness, inability to drink, repeated vomiting, or symptoms that do not improve promptly with cooling and rest. Never leave a person with altered awareness alone in the heat. People with chronic illness, pregnancy, or medicines affecting sweating or fluid balance should be assessed early.

Ask whether the episode was heat exhaustion or heatstroke, how to replace salts safely, when activity can resume, and whether any medicine or health condition increases your heat risk.