Heat Exhaustion vs Heatstroke
Heat exhaustion is overheating with heavy sweating; heatstroke is a life-threatening emergency where sweating stops.
Heat exhaustion is overheating with heavy sweating; heatstroke is a life-threatening emergency where sweating stops.
Also known as
Heat illness, Hyperthermia, Sunstroke, Heat-related illness
Why travellers need to know
Travellers are particularly vulnerable to heat illness because they're often more active than locals (sightseeing, hiking), less acclimatised to the heat, and may not recognise early warning signs. The critical distinction is: heat exhaustion is your body's warning system working; heatstroke is that system failing. Knowing when to stop, cool down, and hydrate prevents the escalation that turns a bad afternoon into a medical emergency.
Real-world example
You're sightseeing in Marrakech in July (42°C). After 3 hours walking, you feel dizzy, nauseous, and are sweating heavily. This is heat exhaustion. You move to shade, drink water, and cool down with wet cloths. If you'd ignored these symptoms and kept walking, your body temperature could have risen above 40°C, sweating could have stopped, and you'd have progressed to heatstroke, which requires emergency hospital treatment.
Country-specific notes
🇾🇪 United Arab Emirates
Summer temperatures exceed 45°C; outdoor activity dangerous
UAE summer (June-September) regularly exceeds 45°C with high humidity. Outdoor activity during midday hours is genuinely dangerous for unacclimatised visitors. Hotels, malls, and taxis are heavily air-conditioned, creating large temperature differentials that stress the body.
🇮🇳 India
Pre-monsoon heat (April-June) exceeds 45°C in many states
India's pre-monsoon season brings extreme heat across Rajasthan, central, and southern India. Heat-related hospital admissions spike during this period. Travellers planning temple visits, desert tours, or Rajasthan itineraries in April-June should plan around extreme heat.
Carry ORS sachets and drink continuously, not just when thirsty. By the time you feel thirsty in extreme heat, you may already be dehydrated.
🇺🇸 United States
US Southwest summer temperatures regularly exceed 45°C — US emergency rooms treat over 65,000 heat illness cases annually
Desert destinations (Las Vegas, Phoenix, Monument Valley) present serious heat risks. Heat exhaustion can progress to heatstroke in under an hour in dry desert heat, especially for visitors unaccustomed to the climate.
In the US Southwest, carry at least 1 litre of water per hour of outdoor activity — thirst is a late indicator of dehydration in desert conditions.
Frequently asked questions
How do I tell the difference between heat exhaustion and heatstroke?
Heat exhaustion: heavy sweating, cool/clammy skin, weakness, nausea, headache. Body temperature may be elevated but under 40°C. Heatstroke: sweating stops, skin is hot and dry, confusion or altered consciousness, body temperature above 40°C. Heatstroke is a medical emergency requiring immediate cooling and hospital treatment.
How do I cool someone down if I suspect heatstroke?
Move them immediately to shade or air conditioning. Remove excess clothing. Apply cold water or ice packs to the neck, armpits, and groin — where major blood vessels run close to the skin. Fan continuously. Call emergency services immediately — heatstroke is life-threatening and requires IV fluids and monitoring.
Your Nomedic record includes medications that affect heat tolerance (diuretics, beta-blockers, antihistamines), giving treating doctors critical context in a heat emergency.