How to spot the signs of heatstoke, hypothermia and dehydration on a round the world adventure motorcycle trip

Dr Mike
Mike Leahy


ABR’s experimental medic Dr Mike Leahy is all too familiar with the effects of riding in extreme conditions. From heatstroke to hypothermia, here’s how to spot the signs it’s time to pull over…

As ABRs, we get our kicks by embracing adventure, regardless of the many risks posed. However, very few of us actually want to kill ourselves because of our passion for adventuring by bike. I believe that the trick is to get as close to the line as possible – without ever crossing it – because if a rider does cross the line it’s likely to involve a one-way trip to a very hot place – and I don’t mean Morocco!

Cold comfort

I’m told by many of my scientist friends that hypothermia is a relatively pleasant way to go (together with drowning). But if you’re not particularly keen on the idea dying it’s a potential hazard that’s worth taking seriously.

Hypothermia is a condition in which the core body temperature drops below that required for normal metabolism (around 35oC). Under normal circumstances our core body temperature is maintained at around 36.5-37.5 degrees, but if exposed to extreme cold for any length of time the body may no longer be able to maintain this. A drop of 1.5oC doesn’t sound much, but it can be lethal.

Mild hypothermia is usually characterised by shivering, increased heart rate, hypertension (high blood pressure) and vasoconstriction (narrowing of the blood vessels). It can lead to mental confusion, but is relatively easy to treat. You simply need to warm up.

Dr Mike

As exposure to low temperature increases, shivering becomes more violent, it becomes difficult to co-ordinate your movements, and you’re likely to become clumsy with slow, laboured responses, a bit like being drunk. It’s at this stage that riding a bike becomes dangerous, so you’ll need to find shelter – and quickly. As surface blood vessels continue to constrict the sufferer is likely to look very pale, with the extremities becoming blue. You may become aggressive, disorientated, unreasonable, or even begin to undress (behaviour which is believed to lead to around one in five hypothermia deaths).

Dehydration and alcohol consumption can increase the risk of hypothermia. Alcohol acts as a vasodilator, increasing blood flow to the skin (hence a drunkard’s red face), causing the body temperature to drop more rapidly . It’s suggested that around a half of hypothermia cases are complicated by alcohol consumption, so leave off the drink if you know you’re likely to become cold in the immediate future – or, indeed, be riding a bike.

It’s not easy to diagnose hypothermia by body temperature alone, because most over-the-counter thermometers are designed to look for abnormally high temperatures, not low ones. Core body temperature can also be tricky to determine by putting a thermometer in your mouth, so the thermometer should really be inserted somewhere far more private. Not something you’ll want to do in front of your mates on a desolate mountain pass! To be honest, if you’re in a cold place and either you or a riding partner are shivering, badly co-ordinated, behaving irrationally, or becoming clumsy, alarm bells should be ringing.

There are a number of ways to rewarm the body, some involving the use of intravenous fluids. Of course you won’t have this option high in remote parts of the Himalaya or Andes, so do yourself a favour and take the proper riding kit, and if you even suspect hypothermia, stop, find shelter, put on all available clothing and snuggle up to your mates – however ugly or smelly they are.

Hot stuff

Higher temperatures can be similarly deadly, and hyperthermia (heatstroke) is the opposite of hypothermia; in other words an elevated core body temperature which occurs when the body cannot rid itself of heat as fast as it’s absorbing it from the environment.

Once a critical temperature is reached (which, like hypothermia, may only involve a change of a degree or two from normal body temperature) a series of chemical reactions within the body can go out of control, causing body temperatures to increase rapidly until reaching lethal levels at around 40C.

One particular consideration which goes against a rider’s intuition is that you should actually cover up, not strip off, when riding a motorcycle in temperatures which exceed normal body temperature, otherwise the warm breeze created by riding will actually act like a fan-assisted oven and heat the body rather than cool it.

The only way that the body can cool itself in such conditions is to sweat profusely. This will not work sufficiently well in extremely high temperatures and will also lead to extreme fluid loss. You may feel a little clammy and uncomfortable while wrapped up, but water loss is drastically reduced.

It’s tricky to distinguish between fever and true hyperthermia, but very important to do so because the causes and treatments are very different. Basically if someone is otherwise healthy, and it’s suspected that exposure to extreme heat or humidity has resulted in heatstroke it’s best to assume that it’s true hyperthermia and not an infection.

Other diagnostic features include hot, dry skin which may appear ‘flushed’ or red, swollen lips, confusion, increased heart rate and increased breathing rate. Dry skin is a dead give-away that the body is unable to cope, because in high temperatures sweat would normally make the skin wet to the touch. Extreme cases of heatstroke can lead to fits, seizures, coma and death. As with hypothermia, if you suspect that you may encounter conditions in which heatstroke is a possibility, avoid drinking any alcohol.

Dr Mike

It’s essential to deal with the first symptoms of hyperthermia as promptly as possible, especially when travelling alone. Drink plenty of water, rest in the shade, but don’t bother taking any fever-reducing drugs such as aspirin or paracetamol – they don’t work for heat stroke! It’s worth trying to soak some spare clothes in water and use them as a sponge to cool your head neck and body. A cool bath, or a dip in a cool stream may help, but if the water’s too cold it will simply lead to the constriction of blood vessels near the surface of the skin. This means that core body temperature can not be lost via these vessels, so the treatment can be counterproductive.

In severe cases, hospitals can use intravenous hydration or even blood dialysis to cool the sufferer down quickly, but as these facilities are unlikely to be available in the middle of nowhere, prevention is far better than cure.

Dry county

Like hypothermia and hyperthermia, dehydration can creep up on the unsuspecting ABR, quickly becoming a serious and life-threatening problem. The main diagnostic features of dehydration are nausea, vomiting, headaches, low blood pressure, muscle cramps, fainting, visual disturbances and dizziness.

In hot conditions, particularly when struggling to muscle a fully laden bike around, it’s easy to become dehydrated, and experts recommend consuming as much as 10 litres of water each day in hot weather. At altitude, the drugs taken to combat altitude sickness can cause premature dehydration, so extra care is needed. Running the risk of sounding like a real killjoy, alcohol consumption is never a good idea in extreme locations. Another obvious risk factor is diarrhoea, because of the associated loss of water in runny poo.

Generally you should aim to urinate the same number of times each day as you usually do (prostate problems apart), and the colour of your urine should not be any darker than usual. If you pee less frequently, or your urine becomes a darker shade of yellow, then drink more. Rationing water is a very bad idea and should only be done in emergencies.

If dehydration is suspected the obvious solution is to drink lots of water, although because salts are also lost through perspiration, these also have to be replaced. There are all sorts of re-hydration powders and liquids on the market, and it’s a good idea to pack some. I know friends in the special forces who are adamant that a couple of digestive biscuits contain sufficient salt to deal with most cases of dehydration, as long as plenty of water is available. Another option is to make a solution using a cup of water, a teaspoon of salt and five or six teaspoons of sugar. My army mates also confirm that drinking your own urine is not a good idea (or drinking anyone else’s for that matter).

Dr Mike

Sun days

So now I’ve put you off cold, hot and dry places, told you that you shouldn’t drink beer, and that you should piss a lot even when there’s a risk of frostbite on your nethers, it’s time to put you off the sun. When riding a bike, the risk of sunburn is very much neglected, but it can be extremely painful, particularly around the nose and neck. The breeze from riding often disguises the power of the sun, so a high SPF sunblock is essential, especially at altitude or in the tropics. A burnt nose looks pretty daft, sunburn increases the risk of skin cancer and facial scarring can be permanent. There’s no point in deliberately trying to look uglier than we already are.

Unlike sunbathing, we tend to keep our eyes open for long periods of time while riding, which on balance is probably a good thing. So, if you don’t take tinted visors or goggles when touring in places which are sunnier than the UK (which, let’s face it, includes most of the globe) a pair of decent sunglasses should also be essential equipment, particularly in deserts or above the snow line. Another factor to bear in mind is that high UV concentrations due to Ozone holes above South America, New Zealand and Australia pose particular hazards including severe eye damage and an elevated risk of skin cancer.

High times

Finally, without wishing to put you off leaving the low-lying comfort of middle England, altitude is also an unpredictable killer. Health problems are caused by the low-partial pressure of oxygen at altitudes above around 2,500m or 8,000ft.

For some people the effects are mild, with breathlessness being the only real issue, for others, oedema (fluid retention), brain damage and death might result. Fitness or your general level of health are irrelevant. A perfectly healthy person can succumb to altitude sickness while a couch potato looks on, feeling no ill effects at all.

Remember, altitude sickness is more serious than simply being out of breath. First indications that you’re becoming ill are headaches, fatigue, stomach cramps, lack of appetite, dizziness disturbed sleep patterns and nausea. At this point it’s prudent to turn back. If the symptoms progress and pulmonary oedema (fluid in the lungs) or cerebral oedema (swelling of the brain) occur you may well die. Progression to the severe stage is gradual and you may not acknowledge the deterioration, but warning signs are a persistent cough, fever, clumsiness, unreasonable behaviour and a gradual loss of consciousness.

The psychological effects of severe altitude sickness are not to be underestimated. While working in the support crew of an international rally crossing Tibet, we actually lost one of the competitors at nearly 18,000ft. He left his vehicle, stripped naked and climbed into a nomad tent, where the bemused inhabitants tried to look after him. Once we found him all we could realistically do was quickly drive down to around 10,000ft, where he recovered sufficiently to be flown home. There’s no high-tech cure for altitude sickness. Even if you miss your goal by turning back, you have to consider whether it’s worth losing your life by continuing with your planned trip.

All of these extremes, and the illnesses caused by them, might be experienced during a single trip. All are quite common, potentially life-threatening, but easily avoided. There is no point becoming paranoid, or allowing worry to spoil your ABR-ing, though. The key is to take simple precautions, know how to recognise the first symptoms of illnesses associated with extreme elements and be prepared to act before the condition becomes serious. Then, the world is your oyster!

Dr Mike

Who’s writing

Adventure motorcyclist Mike Leahy is a virologist and TV presenter who’s passionate about foreign travel. His TV shows include Bite Me for National Geographic, LabRats for BBC3, and Bodysnatchers for BBC1. Mike likes to experiment on his own body. By deliberately infecting himself with nasty diseases, being bitten by dangerous animals, and growing parasites in his insides he hopes his first hand experience will save other adventure motorcyclists from the same fate.