How to Hike Safely in Hot Weather

Summer brings long days and open trails, but heat is one of the most underestimated hazards in hiking.

Climbing under a strong sun can push your body temperature up faster than you would expect,

and the early signs of trouble are easy to brush off as ordinary tiredness.

With smart timing, the right clothing and steady habits on the trail, you can hike comfortably through the warm months.

This guide covers how to plan, dress, drink and pace for the heat, and how to recognize heat illness before it becomes an emergency.

Why Heat Hits Hikers Hard

Walking uphill with a pack generates a lot of internal heat.

Your body sheds that heat mainly by sweating, and sweat only cools you when it evaporates.

In humid weather, evaporation slows, so you sweat heavily without getting much cooler.

In dry heat, you may not notice how much you are sweating at all, because it evaporates almost instantly.

Terrain adds to the load. Exposed rock, sand and pale ground reflect and radiate heat, and canyons can trap it.

Every bit of fluid you sweat out also has to be replaced, or dehydration makes it even harder for your body to cool itself.

Plan Your Hike Around the Heat

Your best tool is timing.

Start at first light so you do most of your climbing in the cool of the morning and finish before the hottest part of the afternoon.

In many places, the most intense heat comes in mid to late afternoon rather than at noon,

so an early finish matters more than an early lunch.

• Choose shade: Forested trails, routes along creeks and slopes that face away from the midday sun stay noticeably cooler.
• Think about elevation: Higher trails are usually cooler than low valleys and deserts.
• Know your water: Research reliable water sources and assume seasonal ones may be dry.
• Scale back: Pick a shorter route than you would in cool weather, with less climbing.
• Check the forecast: Look at the expected high temperature and humidity or heat index, and change plans during heat warnings.

Be especially cautious with routes that go down first and climb out at the end, such as many canyon hikes.

The hardest effort then comes during the hottest part of the day,

when you are most tired. Check local conditions and any seasonal heat advisories before you go.

Dress to Stay Cool

It seems backward, but covering up often keeps you cooler than stripping down.

Loose, light-colored, breathable clothing blocks direct sun while letting air move across your skin.

A lightweight long-sleeved shirt with a collar protects your arms and neck without sunscreen, and a wide-brimmed hat shades your face, ears and neck.

Wear sunglasses, apply sunscreen to exposed skin and reapply it through the day.

Choose breathable footwear and socks, since hot, sweaty feet blister more easily.

A bandana or neck cloth soaked in water acts as a portable cooler, and in hot, dry weather,

this is one of the few times a wet fabric works in your favor.

Drink and Eat With a Plan

Start the hike well hydrated, then drink small amounts often rather than large amounts all at once.

Carry more water than you would on a cool day, and do not count on refilling from a source you have not confirmed.

Sweat contains salt as well as water, so eat salty snacks and consider an electrolyte drink on long, hot hikes.

Drinking large volumes of plain water without replacing salt can dilute the sodium in your blood, a dangerous condition called hyponatremia.

Its early signs, such as nausea, headache and confusion, can look a lot like heat illness,

which is one more reason to balance your drinking with food.

Water-rich foods such as oranges, grapes and cucumber slices add a little fluid along with a welcome cool bite,

and they are easier to face than dry crackers when heat dulls your appetite.

A simple check is urine color.

Pale yellow generally means you are keeping up, while dark yellow or infrequent urination means you need more fluid.

Pace Yourself and Cool Down Often

Slow down on climbs and take breaks in the shade before you feel overheated. Rest stops are your chance to bring your temperature down,

so sit in the shade, loosen or remove your pack, and let air reach your back.

On long exposed stretches, plan each break around shade you can see ahead,

such as a lone tree or a rock overhang, rather than stopping in full sun.

Use water to your advantage.

Soak your hat, bandana or shirt in a stream or lake when you pass one, and splash your face, neck and forearms.

If you hike with others, keep an eye on each other,

because people with heat illness do not always notice their own symptoms, especially once confusion sets in.

Know when to call it.

If you are overheating, running low on water, or finding the trail hotter than you expected, turn around early.

There is no shame in coming back on a cooler day.

Recognize the Warning Signs of Heat Illness

Heat illness exists on a spectrum, from cramps and exhaustion to heat stroke, which is life-threatening.

Muscle cramps during heavy sweating are often the first warning, so treat them as a signal to stop,

rest in the shade and drink water or an electrolyte drink before you carry on.

Learn to tell the two main stages apart:

At the first signs of heat exhaustion, stop and move to shade.

Loosen clothing, cool the skin with wet cloths and fanning, and have the person sip water or an electrolyte drink if they are alert.

Get medical help if symptoms get worse, if the person vomits, or if they do not improve within about an hour.

Heat stroke is a medical emergency. Call for help immediately using your local emergency number or a satellite device,

then move the person to shade and cool them as quickly as you can with water and fanning while you wait.

Do not give the person anything to drink.

A first aid course is the best way to learn these skills properly.

Give Your Body Time to Adjust

Your body adapts to heat with regular exposure, starting to sweat earlier and more efficiently over roughly one to two weeks.

If a heat wave arrives suddenly or you travel from a cool climate to a hot one, start with short,

easy outings and build up gradually.

Some factors lower your heat tolerance on any given day.

Recent illness, poor sleep, alcohol the night before and some medications can all make heat harder to handle,

so take it easier when any of them apply,

and ask a doctor if you are unsure how a medication affects you.

Older adults, young children and people with heart conditions also need extra care in hot weather.

Stay Cool Out There

Hot-weather hiking is about working with the heat instead of fighting it.

Start early, choose shade and water, cover up, drink and snack steadily, slow down, and turn back when the heat says so.

Watch yourself and your partners for warning signs, and act quickly if something feels wrong.