Hill Skill Series – How to survive hiking in hot weather.

Mountaintrails guided hikes.

We all like to hike on clear sunny days, perhaps with a few white fluffy clouds and a light breeze to take the edge off the heat.

However, summer heatwaves do occur, even in these northern climes, and many of us now head to hotter countries like Morocco and Spain to hike and to take trekking holidays. 

 There are inherent dangers to hiking in very hot weather and when the sun is beating down all day, and the most obvious of these are sunburn, dehydration and heat exhaustion.

So how do we cope when the mercury starts rising? And what can we do to minimise these risks?


Recent campaigns to alert us to the dangers of too much sun seem to have sunk home. Now almost everyone is aware of the risk of skin cancer that comes with overexposure to the sun’s ultraviolet rays and subsequent sunburn.

The first line of defence is to apply sunblock to exposed skin, the fair skinned and those not used to the sun should consider a factor 30+ or higher, and reapply during the day if you think you are sweating it off.


Moroccan mule trail

Remember to apply behind the ears and other awkward places, and if you are travelling over reflective surfaces, such as snow, apply below the chin and under the nose. I have seen some painful cases of under-nose sunburn in people travelling over snow for extended periods!

Remember too that at higher altitudes the sun’s ultraviolet rays are stronger, as the air is thinner.

It is also wise to cover exposed skin, widebrimmed sun hats are a must in strong sunlight, and wear longsleeve shirts and long pants to avoid over exposure to the sun.

Consider hiking in the early morning, this is a good strategy in hot weather, and is important in avoiding the other risks areas, dehydration and overheating.


When hiking in hot weather, particularly when slogging uphill, the human body starts to sweat to regulate its core temperature. It is important to replace this lost fluid and the mixture of essential salts, called electrolytes, that it contains.


Dawn in the High Atlas.

One of the first, and most obvious signs of dehydration is feeling thirsty, and this may be accompanied by a headache, dizziness and a feeling of weakness. Another clear indicator of dehydration is dark yellow urine, in a normally hydrated person it should be a pale straw colour.

The muscles need water to function correctly, and a further sign of dehydration may well be cramps in the legs.

To replace these lost fluids drink between 2 and 4 litres of water a day, though this is a generalisation as individuals differ in their needs. Drink when you are thirsty, which makes sense, avoid drinks containing caffeine and alcohol as these are diuretic and will make you pee more.

To replace lost salts mix water 50:50 with fruit juice or add shop bought electrolytes, such as dioralyte, to your water bottle.

Heat Exhaustion

Heat exhaustion is not as severe as heat stroke, but could be considered as a precursor to it.

It is often related to dehydration, and the early signs are the same, headache, thirst, dizziness and dark yellow urine. These symptoms may also be accompanied by confusion, profuse sweating, cramps, rapid heart beat and fainting.


African rain forest, Tanzania.

It is important to cool down, so seek out shade, rest and avoid exertion. Drink plenty of fluids and if possible wet the head and neck. Act quickly to avoid heat stroke, which is a serious condition requiring medical intervention.

To reduce the risk of heat exhaustion it is important to stay hydrated, and to cover up with a wide brimmed hat and wear loose clothing. Try to avoid hiking through the heat of the day, hike in the early morning and rest in the early afternoon, when the heat is most intense.

Wearing a wet cloth around the neck, such as a buff or neckerchief, will help to cool the blood as it passes just under the skin surface at this point.

Heat Stroke

This is a condition resulting from acute overheating of the body, it occurs if the core temperature exceeds 105F (40C).

The symptoms of heat stroke include rapid heart rate, red dry skin, lack of sweating, nausea, confusion and fainting. This is a very serious condition that can result in permanent organ damage or death.

If heat stroke is suspected call the emergency services and begin rapid cooling by seeking shade and spraying or immersing in cold water.

If the symptoms of overheating are treated at the heat exhaustion stage then heat stroke can generally be avoided.

When the temperature soars, cover up to stay comfortable.


Having hiked, climbed and backpacked in temperatures often exceeding 30C, I have found the most important factors in staying comfortable are to remain hydrated and to cover exposed skin. These two alone will help avoid many of the associated problems of hiking in hot weather.

About Author

Russell is the founder and owner of mountaintrails.ie. With over 35 years of mountaineering experience, including expeditions in Europe and Africa, Russell leads many of the trips himself, and is a fully qualified Mountain Leader, has a Rescue and Emergency Care First Aid qualification and is fully insured.


Mike Maunsell
July 15, 2015
Enjoyed your well written advice, applicable to the European alps this year. Looking forward to more of the same. Best wishes, Mike, Mountain Research Ireland.

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