Hot weather can be lethal
This is not a doom & gloom post. Instead, I’m looking at realistic options. Man-made climate change is real, with indisputable evidence backing it up. In real-world terms, we see the effects all around us, in unusual weather patterns, increased flash flooding, and yes, heat waves.
As the planet warms, these heatwaves are going to get more severe, and more frequent, and when most people finally wake up to the survival-level event we’re faced with, and governments finally stop pandering to shareholders, and instead start acting, driving levels will plummet. It will have to – that’s non-negotiable, if we as a species want to survive.
I genuinely expect a massive increase in cycling as a means of transport, and not just a sport or leisure activity. Cycling is the only real personal transport option open to the majority of people – do not for a moment delude yourself into thinking ecars are the answer.
Cycling during a heat wave
So, how do you cycle in a heatwave? Are there things to look out for? Are there sensible precautions you can take? Is it even possible?
To start with, let’s examine how heat affects your body. This will be over-simplified, so medical professionals, please just grin and bear it?
Have you ever gone for a bike ride on a cold but dry winters day, and got back home drenched in sweat? I’m stating the obvious here when I say that physical exercise generates significant body heat. That’s very welcome in mid-winter, but less welcome when riding during a heatwave.
Most people have a normal body temperature of around 37 to 38 degrees Celsius. We have really only 1 way to cool our bodies down: the cooling effect of sweat evaporation. When our body temperature rises above 38 degrees, blood flow to the skin’s surface is increased, leading to increased sweat. Usually, that’s enough to reduce our core temperature, or at least keep it from rising further. At this point, when cycling on a sweltering hot day, and your body is generating more heat than can be dissipated by sweating, you may start experiencing headaches, and you’ll also start feeling fatigued. This is heat fatigue, and usually sets in when your core temperature starts hitting around 40 degrees. In case you didn’t realise it, this is your body telling you that you are being stupid, and need to stop.
Internal organ shut-down
If you carried on, your core temperature will rise further. At around 41 degrees, you’ll probably stop sweating altogether, and some of your internal organs will shut down. This is your body flashing blue lights at you, telling you to immediately stop and get into the shade! To put it into perspective, this is the start of heat stroke, and heat stroke kills people. You risk total organ shutdown, and lasting brain damage, if your core temperature reaches 42.
Have I scared you enough yet? Heat stroke is deadly, and it’s vital you recognise the signs early on. If in doubt, err on the side of caution. Slow down, and consider taking an extended break during the hottest part of the day. There are other factors that can make heat exhaustion worse: drinking alcohol, or consuming caffeine, as both of those increase dehydration.
At this stage, you might be thinking that you need to drink more water. Well, sure, you do, but overhydration is a risk that could do more damage than dehydration. Usually, a good indicator is your wee. For starters, if you’re not weeing as often as normal, you’re not drinking enough. The colour of your wee will also tell you much – if it’s very dark yellow, you’re not drinking enough. Equally, if you need to wee more than usual, or if your wee is clear like water, you’re drinking too much. Getting the balance right is important, and usually consists of drinking often, before you get very thirsty, but drinking little at a time.
When you sweat, your body will lose much minerals, and ideally these must be replaced. However, take some advice before going down the DIY route, or stick with purpose-made supplements that you add to your water bottles, as the average westerner already consumes far too much salt in their normal diet.
Plan your day’s riding to set off well before it’s very hot, and fit in a long mid-day break (just remember it’d be harder to get going again after a long break). Go slower than you would on a mild day, and stop often. Whenever possible, find shade when you stop.
Ice-cream. For health reasons
When cycle touring, the only calorie-watching you usually have to do is to ensure you get enough calories in, so having a few ice-creams along the way would help lower your core temperature a bit. You’ve never before been told to eat ice-cream for health reasons, have you? Whenever there’s a risk of high temperatures, check out the route on a map first, so you know where there are points where you can fill your water bottles. And fill your bottles religiously, at every available opportunity. Yes, even if they’re still mostly full.
Hot days are often sunny, so ensure you have Factor 50 (at least) sun-block with you, and re-apply it often, as sweat will wash it off. After all, you don’t want to ruin a great cycle tour by getting badly sunburnt, do you? Consider covering up completely, but do yourself the favour of wearing light-coloured items of clothing. Black, or dark colours will not be your friend! Especially if you don’t wear a helmet, consider wearing a hat with a brim – your ears, neck and nose will thank you later when they’re not badly sunburnt.
Prevention is always better than cure, but what if you cannot avoid riding when the day it at its hottest? In such cases, be very careful, and pay attention to your body. Cycle slower than you otherwise would have done, and stop as often as you can.
Call for help
Finally, if there’s even a reasonable suspicion that someone you’re riding with has sunstroke, call for medical help. People die from sunstroke! If they’re acting confused, get them off the bike, into shade, pour water over them to cool them down, and also fan air at them, and call 999. If there’s really no shade around, get some clothes, or a towel from your panniers and hold it up, so you become the source of the shade that shelters them.