A must for nature lovers, hiking is hugely popular in summer. Yet heatwaves can pose real dangers. Taking the necessary precautions is essential to enjoy the trails safely. Here is everything you need to know about hiking in the heat.
What are the risks of heat when hiking?
Hiking in high temperatures, especially during a heatwave, presents several hazards. The most serious is heat stroke, or hyperthermia. It occurs when the body can no longer regulate its temperature, causing high fever, severe headaches, nausea, vomiting, and confusion. Without prompt treatment, it can lead to fainting, loss of consciousness, or even death.
In high heat, your body loses large amounts of water through sweat while hiking. Without adequate hydration, you risk suffering from dehydration. Symptoms vary in severity and typically include intense thirst, unusual fatigue, dizziness, or headaches.
Another less common risk is hyponatraemia, caused by a lack of salt. It can occur if electrolyte loss is not replenished. Although rare, it is dangerous and can affect brain function.
Finally, sunburn poses a real danger to your skin. Beyond the immediate discomfort, it can cause long-term health issues, including premature skin ageing and an increased risk of skin cancer.
When should you set off to avoid the heat?
To beat the heat while hiking, we recommend adjusting your summer schedule. Temperatures typically peak between 12 pm and 4 pm, when the sun is highest and the air is warmest.
The best tip for avoiding the heat is to set off very early and finish your hike before midday. You will enjoy cooler air, quieter trails, and significantly reduce the risk of feeling unwell.
Another great option is to set out in late afternoon or early evening—just remember to bring a headlamp and monitor the time so you are not caught out after dark. Heading out at these unusual hours is a fantastic way to experience the mountains from a fresh perspective.
On a full-day hike, take advantage of the shade and rest in the shade during the early afternoon to recover and lower your body temperature before moving on.
During a heatwave, it is sometimes wiser to cancel your hike. If temperatures exceed 30 or 35 degrees, if there are long exposed stretches, or if some participants are less fit, we recommend postponing your outing for safety.
How to stay safe from the heat when hiking?
Along with adjusting your departure times, several practical tips will keep you safe from the heat when hiking. Adapt your route, fine-tune your gear, stay well hydrated, and protect your skin.
Apply SPF 30 to 50 sunscreen regularly to all exposed areas of your body. Do not overlook commonly missed spots like ears, neck, and behind the knees. In addition to drinking frequently, be sure to cool down during your hike. You can dip your forearms or neck in a stream, or wet your cap, hat, or buff.
The best way to protect yourself from the heat when hiking is to adapt your route. Choose a circuit with plenty of shaded areas. In summer, woods provide the perfect protection against the sun. You can also walk near a stream or lake to cool down if needed. Remember to take frequent breaks in the shade.
To minimise risks, adjust your itinerary according to the temperature. Skip steep climbs and intense hikes in favour of gentler walks at a steady pace.
How to stay properly hydrated when hiking?
Staying well hydrated is vital when temperatures rise, especially when hiking. Before you even set off, drink enough water and identify water points along your route. Beyond carrying a good amount of water for hiking—at least 2 litres—you can also take a filter bottle, purification tablets, or a water filter.
Throughout your effort, remember to drink regularly in small sips. Never wait until you feel thirsty to hydrate: thirst is already a sign of dehydration. We recommend using a hydration bladder or an easily accessible water bottle so you can drink continuously on the trail.
When choosing what to drink, stick to water and avoid sugary drinks or alcohol. To prevent hyponatraemia, add a pinch of salt to your water or take isotonic drinks or electrolyte tablets to replace lost minerals.
For long hikes, prepare light meals that are easy to digest. Pack snacks rich in water (fruit, fruit purées) and fast-acting carbs (dried fruit, energy bars).
After your hike, make sure to drink mineral-rich beverages, sparkling water, or diluted fruit juices to aid recovery.
What clothes should you wear in a heatwave?
Clothing is a great barrier against heat on the trails. It needs to be lightweight, breathable, and protective to shield you from the sun. Light-coloured fabrics are recommended, as they reflect light rather than absorb it.
Opt for breathable technical T-shirts that cover your shoulders. In intense sun, long sleeves are a great option. Synthetic fabrics or fine merino wool are recommended for wicking away sweat, while cotton should be avoided. For enhanced protection, you can also choose UV-protective clothing designed to shield you from the sun's rays.
Your bottoms should be comfortable and airy. Wear shorts or lightweight trousers, depending on your exposure to the sun, brush, and ticks. Convertible trousers are a great compromise in summer. In all cases, opt for stretch, breathable fabrics.
To protect your head, hiking caps and hats are essential. Wide-brimmed hats have the added benefit of covering your head, face, and neck all at once. Category 3 or 4 sunglasses are also indispensable for protecting your eyes.
Finally, do not forget technical fibre socks. They wick sweat away and reduce friction. Opt for low-cut hiking shoes and avoid waterproof models, which tend to trap heat.
As you can see, hiking in the heat is completely doable, as long as you prepare properly. Adjust your schedule, gear, and route to make the most of the trails. In extreme heatwaves, do not hesitate to postpone your hike for safety.
