Follow these tips to keep cool outdoors and avoid injuries such as heat exhaustion and heatstroke.
With global temperatures on the rise in many places, warmer weather is becoming more common. This can make overheating, and potentially heat injuries, more of a problem if we aren’t well prepared. We will look briefly at heat exhaustion and heatstroke and how to recognise them. First aid training will tell you how to treat these, whereas here we will concentrate on avoiding overheating in the first place. Read on for my tips to keep cool while outdoors, gained through years of experience guiding outdoor activities in Scotland and abroad.
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Heat injuries and the importance of keeping cool outdoors
We humans can survive extreme cold far better than extreme heat. For instance, casualties have survived drops in core body temperature of over 20°C. But an increase of only 3°C in core temperature is often fatal without advanced medical care. If you are active in hot weather, it is worth being familiar with the signs of dangerous overheating (so-called ‘heat injury’ or hyperthermia). The early stage is called heat exhaustion and the later, very dangerous stage is heatstroke. Casualties can deteriorate extremely quickly and dehydration and sunburn are often contributing factors.
| Body temp | State | Symptoms |
|---|---|---|
| >40°C | Heatstroke | Flushed dry hot skin ‘Bounding’ pulse Headache Dizziness Confusion Loss of consciousness Fitting |
| 38-40°C | Heat exhaustion | Nausea Loss of appetite Pale, sweaty skin Cramps in stomach / arms / legs |
| 36-37.5°C | Normal body temp |
Sunburn may also be a risk in these situations (although it is caused by excess UV light rather than heat). Keeping cool is therefore more than just about staying comfortable, but it helps us avoid potentially severe sun and heat injury. Read on for my staying cool tips for the outdoors.
1. Keep cool with well-chosen outdoor clothing
The Layering Principle is the secret to staying cool and comfortable outdoors. When hiking in Scotland, for example, we recommend wearing loose-fitting layers and light colours (which reflect sunlight better than dark ones). Cotton can be good in hot weather, but it takes ages to dry. Rainproof jackets and trousers can quickly lead to overheating in warm conditions, so save them for when it’s actually raining! Your head is particularly exposed to sun damage and overheating, so wear a lightweight visored or brimmed hat or scarf/Buff. Although sleeveless tops/T shirts and shorts are nice and cool, they offer less protection against sunburn and insect and tick bites, so choose carefully.
Adjust on the move
Instead of adding and removing layers constantly, try adjusting them. Open vents, zips and cuffs, remove hoods and roll up sleeves to dump excess heat when working hard. Remember, your hands and head have a particularly rich blood flow, so they will also shed heat quickly when uncovered.
Check the forecasted temperature. Good weather forecasts are easily accessible, so use them to plan your clothing choices. In Britain, the Met Office produces excellent specialist mountain and sea forecasts.
2. Lower pace and plan rest stops
Working too hard and/or carrying too heavy a load can easily lead to dangerous overheating. If you are going too fast or the conditions are too challenging, slow down or have a rest, if it is safe to do so. A slower, more sustainable pace with regular planned rest stops, is often just as quick overall (if not quicker) than a pace that is too fast.
3. Carry less weight
It sounds obvious, but carrying less (or lighter) gear can mean less effort and so less overheating. In places with changeable weather and remote terrain like Scotland, this can be more of a challenge, especially during high-intensity sports like mountainbiking. However, learning what to pack and what to leave behind requires experience and good judgement. Get expert advice on what gear and spares to carry and beware of carrying lots of items ‘just in case’. If you are overweight or have low fitness levels you may overheat more easily, so take special care not to overload yourself.
4. Seek breeze, shade or water
A well-planned route can help you avoid overheating. The air is cooler and flows faster over ridges, summits and headlands. If you are sheltered by forest or hills, moving into a more exposed area can cool you down (but might also expose you to more sunshine).
If you can’t find more shade or breeze, cool yourself with water from the environment. The advantage of this is it doesn’t have to be drinkable. Wet your hat or T shirt to get an instant cool-down. Wearing wet bandannas on your wrists quickly cools you because blood flows very close to the surface of your skin there. Bathing your feet in a stream is another great way to cool off, and if it is safe to do so, a quick dip or swim is sure to bring your body temperature down. Watersports safety gear such as PFD, helmet and drysuit can lead to overheating but in Scotland, for example, canoeing and kayaking on cool lochs and coastal waters quickly solves that problem!
❤️ If you are very hot, enter cold water slowly to avoid stressing your heart.
5. Hydrate properly to keep cool outdoors
Effective hydration is vital if you are running hot. With every breath, you will be losing water vapour, and if you are sweating, you will be losing large amounts of liquid water. This moisture must be replaced for your vital organs to function correctly. See this post to get tips on staying hydrated.
☠️ Water is a vital part of your body’s cooling system. Untreated dehydration, together with overexertion, can quickly lead to severe or even fatal heat injury.
6. Time activity to avoid heat
Timing can make all the difference to you comfort levels outdoors. To avoid a hot, sweaty ascent, start earlier when the sun is low. Avoid the hottest part of the day if you expect to be working really hard. Or even plan your journey for a cooler time of year.
So, avoiding overheating is an important part of travel health. Like staying warm, it takes a little effort and planning to stay cool. If you don’t, you run the risk of becoming very uncomfortable, inefficient and, perhaps, dangerously unwell. But if you pay attention to your body and make a few adjustments, you should be able to enjoy your outdoor activities all the more.
Outdoor activities in Scotland with Arc Guiding
Heat exhaustion is a heat-related illness where the body’s core temperature has risen to above 38C (100F). At this temperature, the body is working very hard to keep the core temperature from rising any higher. Urgent medical help is needed to prevent heatstroke.
Heatstroke is a medical emergency arising from untreated heat exhaustion. It occurs when the body’s core temperature has risen to over 40C (104F). At this temperature, damage occurs to the heat-controlling region of the brain (the hypothalamus). This leads to failure of the sweating response and more overheating. This can quickly be fatal.