Advice on Hyperthermia
As the UK temperatures soar and many of us escape the great indoors to maximise our time in the great outdoors, it is essential to have an understanding of heat related problems. Here is a quick run down of what to look for, what to do and, most importantly, how to stop this wonderful hot weather causing a potentially life threatening problem.
What is the problem?
In any weather our body balances heat gain and heat loss to regulate core temperature - hyperthermia (which comprises two related conditions called heat exhaustion and heatstroke) occurs when gain exceeds loss. Heatstroke may follow heat exhaustion but, in reality, it is easy to miss the early signs and you may only realise there is a problem when the casualty is further down the road - the key thing is to be constantly vigilant to managing yourself and others in hot weather and to be effective in spotting the key signs.
Avoidance is key
It is always better to avoid a problem rather than try to solve a problem. Here are some avoidance tips for anyone operating in hot weather.......
1. Protect yourself
- The old Aussie phrase ‘slip slap slop seek slide’ still rings true. ‘Slip’ on a shirt, ‘slop’ on high protection suncream, ‘slap’ on a sunhat, ‘seek’ shade (if you heading off the beaten track you can’t always be in the shade but some good route planning and at least finding shady rest spots can help) and ‘slide’ on sunglasses.
2. Plan and control your liquid intake (don’t wait to rehydrate)
- You can often identify suitable drink sources from maps so you will know where bottles can be topped up. Use them! I often take a break by a stream and slug back any remaining water before refiliing. I always purify water taken from watercourses.
- Evaporative cooling is also really effective so pour some of that cool water from the stream over your head or soak your hat in it. As the liquid evaporates it will help cool you down.
- Drink plenty before you head out for the day, carry a bottle to drink on your journey to the trailhead and then drink stacks when you finish your day (not alcohol!).
3. Dress for the occasion
- Light coloured loose and wicking clothing is better than heat absorbing dark threads.
- Control your layering to stay as cool as possible (‘don’t hesitate to ventilate’).
4. Consider your food intake
- Replace lost salts by taking some salty snacks - salted peanuts or crisps work well.
5. Manage the conditions
- If you plan carefully most of the potential problems the heat may cause might be managed before you've even left your house. Have you carefully checked the weather forecast? Is the route suitable? Are the group prepped and appropriately equipped? Have you taken account of avoiding the hottest part of the day for that long ascent? And so on.....good planning is key.
- Don’t push yourself (or other party members) too hard in hot weather. Take regular breaks in the shade, drink regularly, cut the route short if needed (plan routes with escape options) and monitor the group carefully whilst out.
Who gets affected by heat illness?
Anybody - Hyperthermia can occur in otherwise healthy and fit people of any age who undertake exertion in hot conditions. It can even occur without exertion when exposed to high temperatures for several days (those with pre existing medical conditions are particularly susceptible).
What do you see?
As soon as the brain starts to struggle the problems will start to show - you just need to be able to spot them.
Early signs can include:
- Behaviour changes
- Excessive sweating
- Fatigue, dizziness, headache and vomiting (may appear as flu like symptoms)
- Cramps (can be caused by dehydration and salt depletion
- The casualty may be very thirsty
Later signs are an indicator of heatstroke and at this stage the bodies temperature will be very high (potentially around 40 degrees or more). The signs will include:
- High temperature
- Hot red and dry skin (the body has stopped trying to cool itself down by sweating)
- Rapid pulse/breathing
- Lowered levels of alertness and potentially becoming unresponsive
- Seizure (or series of seizures)
What you can do for someone suffering from heat illness?
- Stop the activity and get casualty somewhere shady (or create shade) and, if possible, cool
- Give them plenty to drink (water is key but adding hydration salts in the right dose will also help if available)
- Cool them down. If you don’t have access to plenty of cool water soaking some clothing or a scarf and putting that on their neck or wrists works well. The evaporative cooling effect is key and so you can assist this up by fanning them as well.
- Monitor the casualty and start planning ahead. What are your best options from this point? If you need to seek advice calling the emergency services will allow you to access professional advice and, if needed, they can help create an onward plan with the ambulance service or mountain rescue services. Heatstroke is a life threatening emergency so get help on the way.
- Manage your casualty. If they have a low alertness level put them into a safe airway position.
- If they have a seizure (or more than one) keep them protected from things that may harm them and time how long the seizure(s) last.
- Be prepared to give CPR if they stop breathing or breathing is not normal.
Posted by Paul