MinimalistRunning and walking in hot weather
To run or walk safely in hot weather, go early in the day, slow down and go by effort instead of pace, carry water for anything longer than about 45 minutes, and stop at the first sign of dizziness or nausea. Your body can adapt to heat, but it takes a week or two, so ease in.
Heat is not a reason to stop moving for the whole summer. It is a reason to change how you do it.
Why heat makes running feel so much harder
When you exercise, your muscles produce heat. To get rid of it, your body sends more blood to the skin and sweats. On a hot day, that cooling system and your working muscles compete for the same blood supply, so your heart has to beat faster to keep up.
The result: a pace that felt easy in spring can feel hard in July. Humidity makes it worse, because sweat evaporates more slowly and cools you less. This is normal physiology, not a sign you’ve lost fitness.
When is the best time to run in summer?
- Early morning is usually the coolest part of the day, and the sun is low. For most places, this is the best option.
- Late evening is the second choice. Air temperature drops, but pavement and buildings release heat for hours after sunset, so cities can stay warm well into the night. If you go out after dark, see our tips for staying safe and seen at night.
- Midday to late afternoon is generally the hottest and sunniest window. Avoid it on hot days if you can.
Check the local forecast and any heat warnings, not just the temperature. A heat warning is a good day for a short walk in the shade, an indoor session, or a rest day.
How much should you slow down?
There is no exact formula, so go by effort. Keep your usual easy runs at a conversational effort — if that means running a minute per kilometer slower, or adding walk breaks you don’t normally need, that is the right call.
Some practical adjustments:
- Shorten your planned distance on very hot days.
- Swap hard workouts for easy ones, or move them to a cooler day.
- Use planned walk breaks; the run-walk method works especially well in heat.
- Don’t chase your usual pace. Comparing a summer run with a spring run on the same route will look worse, and that’s fine.
Our guide to easy effort training explains why effort is a better guide than pace in conditions like these.
What to drink, and how much
- Start hydrated. Drink normally through the day before you go out. Pale yellow urine is a reasonable everyday sign you’re in good shape.
- Under about 45 minutes: most people are fine without carrying water, as long as they drink afterward.
- Longer than that, or very hot: carry water, or plan a route past drinking fountains. Sip regularly according to thirst.
- Long, sweaty sessions: for runs or hikes lasting well over an hour, a drink with electrolytes (or salty snacks) can help replace what you lose in sweat.
- Don’t overdo it. Drinking far more than you sweat out can also be harmful. Drinking to thirst works well for most people on everyday runs and walks.
What to wear in the heat
- Light, loose, light-colored clothing made from technical fabrics that wick sweat. Cotton gets heavy and stays wet.
- A cap or visor to shade your face, and sunglasses.
- Sunscreen on exposed skin, including ears and the back of your neck. Choose a sweat-resistant one.
- Thin socks that wick moisture, which helps prevent blisters as feet swell and sweat.
A small trick some people like: wet your cap or a neck buff with cold water before you head out.
Choosing a summer route
A route can make a bigger difference than any gear:
- Look for shade: tree-lined streets, parks, riverside and forest paths.
- Run loops close to home instead of one long out-and-back, so you can cut it short easily.
- Plan to pass water fountains, or loop past your front door to grab a drink.
- Grass and trails often feel cooler than asphalt, which absorbs and radiates heat.
If you need fresh ideas, see how to find new walking routes near you.
Getting used to the heat
Your body adapts to heat with regular exposure: you start sweating sooner, your sweat gets more dilute, and your heart doesn’t have to work as hard. Most of this adjustment happens over roughly one to two weeks of regular, moderate exercise in warm conditions.
So in the first hot spell of the year, or when travelling somewhere warmer, keep sessions short and easy for the first week or so, then build back up gradually.
Warning signs: when to stop
Stop, get into the shade, and cool down if you notice:
- dizziness, light-headedness or feeling faint,
- nausea or headache,
- muscle cramps,
- unusual tiredness or weakness,
- heavy sweating with cold, clammy skin, or goosebumps in the heat.
These can be signs of heat exhaustion. Drink water, rest somewhere cool, and loosen clothing.
Call emergency services if someone becomes confused, slurs their words, faints, has a seizure, or has hot skin and isn’t improving after cooling. These can be signs of heat stroke, which is a medical emergency.
Some people are more sensitive to heat, including older adults, people who are pregnant, and those with heart conditions or taking certain medications. If that’s you, check with your doctor about exercising in hot weather.
A note on your phone
Phones get hot too. An iPhone left in direct sun can warn you it needs to cool down and may dim the screen or limit some features. Keeping it in a pocket, belt or shaded armband helps. With Minimalist, tracking keeps running with the screen locked, so there’s no need to keep the display on in the sun.
FAQ
Is it OK to run every day in summer?
If you’re used to running regularly, yes, as long as you adjust for the conditions. On the hottest days, an easy walk or a rest day is a perfectly good choice.
Is walking in the heat safer than running?
Walking produces less body heat, so it is generally easier to manage. The same precautions still apply on very hot days: timing, shade, water and listening to your body.
Should I train on a treadmill on hot days?
An air-conditioned gym or a cool indoor space is a sensible option during heat waves. Just keep the effort easy, since indoor running can feel warm too without a breeze.