Heat exhaustion and heatstroke represent two distinct levels of heat-related illness, each requiring different responses. Heat exhaustion occurs when the body loses excessive fluids and salt through sweating, causing core body temperature to rise between 104 and 105 degrees Fahrenheit. Symptoms include dizziness, nausea, headache, muscle cramps, and heavy sweating. The condition remains dangerous but reversible with immediate cooling and hydration.
Heatstroke escalates beyond heat exhaustion into a medical emergency. Core temperature climbs above 105 degrees, overwhelming the body's cooling mechanisms. The sweating stops. Mental confusion sets in. Skin becomes hot and dry rather than clammy. Some people experience seizures. Without rapid intervention, heatstroke damages vital organs and causes death.
The critical distinction lies in the body's response system. During heat exhaustion, sweating still functions as the cooling mechanism, though inadequately. During heatstroke, that system fails completely. This shift marks the transition from manageable to life-threatening.
First aid differs accordingly. Heat exhaustion victims benefit from moving to shade, drinking fluids, and applying cool water to skin. These measures restore the body's ability to cool itself. Heatstroke demands emergency services. Call 911 immediately. Cool the person aggressively with ice packs, ice baths, or cold water while waiting for paramedics. Do not wait for symptoms to improve.
High-risk groups include elderly people, athletes, outdoor workers, and those taking certain medications. Even young, healthy individuals can progress from heat exhaustion to heatstroke in hours during extreme heat waves. Prevention through hydration, rest in shade, and lighter clothing protects against both conditions. Recognizing when someone has crossed from heat exhaustion into heatstroke determines whether they receive treatment in time.