Heat stroke is a serious medical condition that occurs when the body overheats, usually due to prolonged exposure to high temperatures or strenuous physical activity in hot weather. It happens when the body's temperature regulation fails, leading to a core temperature of 104°F (40°C) or higher. Symptoms may include confusion, rapid heartbeat, and hot, dry skin. If not treated promptly, heat stroke can cause damage to vital organs and can be life-threatening. Immediate actions include moving the person to a cooler place, removing excess clothing, and applying cool water or ice packs. Seeking emergency medical help is crucial for recovery.