When to Worry About Heat Intolerance With Heat Exhaustion

Heat Intolerance is a common presentation of Heat Exhaustion, but worsening symptoms, confusion, fainting, or inability to drink require urgent medical care. Move away from heat and begin cooling as soon as symptoms appear. If the person does not improve promptly, or develops signs affecting alertness, breathing, or circulation, contact emergency services.

Most people with Heat Exhaustion notice heat intolerance because the body is struggling to lose heat and replace fluid and salt lost through sweating. You may feel unusually weak, dizzy, headachy, nauseated, clammy, or very thirsty. The skin can feel cool and moist even though the person feels overheated. Heat intolerance can continue after leaving a hot environment, especially after exertion, illness, or poor fluid intake.

Heat exhaustion can become more serious when cooling and drinking do not relieve symptoms. A person who becomes confused, unusually drowsy, unsteady, or unable to respond normally needs immediate assessment because these changes may signal dangerous overheating.

Stop exercise or work and take the person to a cool, shaded, or air-conditioned place. Loosen or remove unnecessary clothing, apply cool wet cloths, and use a fan if available. If they are awake and able to swallow, offer frequent small sips of cool water or an oral rehydration drink. Keep watching their alertness and breathing, and stay with them while they recover.

Do not give drinks to someone who is confused, vomiting repeatedly, having a seizure, or too drowsy to swallow safely. Do not leave an unwell person alone in a hot room or vehicle.

Call emergency services if the person faints, becomes confused, has a seizure, cannot stay awake, has trouble breathing, develops chest pain, or cannot drink without choking or vomiting. Seek urgent medical care when symptoms are severe, keep worsening, or do not start improving after cooling and rest. A very hot body with altered behaviour is an emergency.

Arrange medical advice sooner for a child, older adult, pregnant person, or someone with heart, kidney, or other long-term illness. Medicines that affect sweating, fluid balance, or blood pressure can also increase concern, so bring the medicine list to the assessment.

Ask what may have triggered the episode, how much activity and heat exposure to avoid while recovering, and which fluids are suitable for you. Ask whether any medicine or health condition could make heat intolerance worse, and which symptoms should prompt emergency help if they recur.