How do I hike safely in hot weather?
Hydration and timing
In hot weather, your body loses fluids fast through sweat. Drink before you're thirsty—aim for about 0.5 to 1 liter per hour depending on heat, exertion, and your sweat rate. For hikes over 2 hours in high heat, bring electrolytes to replace sodium and potassium lost in sweat. Water alone can lead to hyponatremia if you drink excessively without salts.
Plan your hike for early morning or late evening, and avoid the 10 a.m. to 4 p.m. window when the sun is strongest. Check the heat index, not just the temperature—humidity makes it harder for your body to cool down. If the forecast is extreme, choose a shaded forest trail or postpone.
- Start before sunrise or after 4 p.m.
- Carry at least 2 liters for a short hike, more for longer.
- Use electrolyte tablets or sports drinks for long, sweaty hikes.
- Take frequent breaks in shade.
- Wear a wide-brimmed hat and light, loose, long sleeves.
- Use sunscreen and reapply every 2 hours.
Recognize heat illness
Heat exhaustion symptoms include heavy sweating, weakness, dizziness, nausea, and muscle cramps. If you feel these, stop, move to shade, drink fluids, and cool down with wet cloths. Heat stroke is a medical emergency: hot, dry skin (or sometimes sweating), confusion, and a body temperature above 104°F (40°C). Call 911 and cool the person aggressively with water and ice.
Prevention is about pacing and awareness. Don't push through warning signs. Hike with a buddy who can watch for confusion or clumsiness. If you're not acclimated to heat, take it easy for the first few days. And remember that some medications, like antihistamines and diuretics, can increase heat sensitivity.
Common mistakes
- Drinking only when thirsty—by then you're already mildly dehydrated.
- Wearing dark, tight clothing that absorbs heat and traps sweat.
- Ignoring early signs of heat exhaustion, which can quickly progress to heat stroke.
