Hiking earlier isn't enough during a heatwave – here's what experienced hikers do instead
Beating the alarm clock is great, but staying safe and comfortable on the trail takes a lot more than an early start
"Start early" is probably the most common piece of advice you'll hear before heading out on a hike during a heatwave.
And for good reason, as walking before the hottest part of the day can significantly reduce your risk of heat exhaustion.
But while an early start certainly helps, it's far from the only thing that matters.
Factors such as trail conditions, humidity, tree cover and even the type of rock beneath your feet can have just as much influence on how hot you'll feel.
Here's why seasoned hikers look beyond the clock when temperatures soar.
The trail itself can become a radiator
Not all hiking routes feel the same on a hot day. Exposed, rocky areas, such as paved paths, can absorb solar energy throughout the morning before radiating it back into the air, which means even if the thermometer reads a comfortable 22°C, the ground around you can feel significantly hotter.
Woodland trails tend to stay cooler thanks to shade and lower surface temperatures, while routes that hug rivers or pass through valleys often benefit from slightly lower ambient temperatures, too. Nothing beats a bit of water spray from a nearby waterway on your morning walk.
UV doesn't wait for lunchtime
Many hikers assume they're safe from the sun before midday, but ultraviolet radiation peaks independently of air temperature.
On clear summer mornings, UV levels can already be high by 9 am, especially at higher elevations where there's less atmosphere to filter the sun's rays.
That means sunscreen, sunglasses and UPF clothing should be part of your kit from the moment you leave the car park, not something you reach for during a coffee stop.
You can also use sun hoodies and hats to shield against harmful UV radiation.
Humidity can be just as challenging as heat
A dry 28°C can often feel more comfortable than a humid 24°C. When humidity rises, sweat evaporates more slowly, making it harder for your body to cool itself naturally.
That's why even relatively modest temperatures can leave you feeling drained if the air is heavy. Checking the humidity forecast before setting out can be just as useful as checking the day's maximum temperature.
Before setting off, look at both the humidity (or, even better, the dew point). A 24°C day with 80% humidity can feel more draining than a dry 30°C because sweat evaporates much more slowly. If the dew point is above 20°C, expect conditions to feel sticky and plan for more breaks, extra fluids and a slower pace.
Higher isn't always cooler
Heading uphill often brings cooler air, but sadly, it's not a guarantee. Many exposed mountain routes offer little or no shade, leaving you under direct sunlight for hours at a time.
On still days, the lack of airflow can make ridges feel surprisingly oppressive despite lower air temperatures. By contrast, a lower woodland walk with dense tree cover may feel considerably more comfortable.
Plan around water and shade
Experienced hikers don't just think about where they're walking but also consider where they'll stop.
Rest breaks in shaded woodland, beside streams or near lakes allow your body to cool more effectively than standing in full sun on an exposed hillside.
Applications such as ShadeMap can give you a rough idea of where the shade will fall in the coming days. If your route offers little natural shade, consider shortening it or saving it for cooler conditions.
They're also ideal places to top up water, have a snack and bring your heart rate back down before continuing. You can set reminders to take water on certain Garmin watches.
Your pace matters more than your finish time
Don't become fixated on maintaining your usual hiking speed in high temperatures, as your heart rate naturally rises in hot weather as your body works harder to regulate its temperature.
As a result, you'll often feel like you're putting in more effort even when walking at the same pace. Slowing down, taking more frequent breaks and drinking little and often can help you finish feeling pleasantly tired.
Apple Watches, Samsung's Galaxy Watch range, Garmins and Google's Pixel Watch all offer high heart rate alerts, which is worth setting up before your big hike.
An early start remains one of the best ways to stay comfortable during a summer hike, but by considering terrain, shade, humidity, and your own effort level, you'll often have a much more enjoyable day outdoors.
