Riding When it’s Hot: 14 Tips to Keep You Safe

The stoplight ahead turned yellow. I looked in my rearview mirror and saw the car behind barreling towards me. It was a 30 mph/50 kph zone, but he’d flagrantly surpassed that, so hell-bent was he to get through the yellow light. There was only one problem. I was in front of him, and I had already stopped.

It was late afternoon, and I had been riding for almost seven hours on my way home from Gatineau, QC, on a feels-like 107º F/42º C day. I was finishing a 3800-mile (6,000-kilometer) tour of Nova Scotia and The Cabot Trail and was only ten minutes away from my home. If anyone had an excuse to be less than fully alert, it was me. Fortunately, I was on my game, so I jumped on the throttle and steered my motorcycle out of his path as he bolted, hell-for-leather, through the red light, missing me by mere inches.

Riding in high temperatures can get you in trouble in more ways than one. In this case, it would have been because it had made me tired and affected my concentration. In other cases, it can be because of  heat illness. I had protected myself by keeping myself covered from the sun. I wore a water vest, neck-cooling dickie, and a Camelbak water bladder backpack, so I could stay hydrated by continuously drinking throughout my ride. It was this gear that kept me fresh and alert. I credit it for saving my life.

This article is about how to keep yourself safe while riding on our ever-more frequent high-temperature days.

Temperature, heat, and how our body cools itself

When it’s cold, we know what to do; we put on more clothes. When it’s hot, many riders erroneously think: take off clothes. But, instead of cooling down, this can have the opposite effect. To understand this, we require a little knowledge about heat, temperature, how our bodies cool themselves, and the science behind it all. Knowing this can keep us safe while riding in the blazing sun.

For science, I turned to energyeducation.ca. Temperature, it states, is a measurable physical property of an object or system, i.e., how hot or cold it is. Heat is the transfer of energy between objects or systems.

There’s one more thing we need to know. Part of the Second Law of Thermodynamics states that heat will always flow from hotter substances or systems to colder ones. This is evident when we leave a cup of coffee on a table. It will give off heat to the surrounding air and eventually end up at room temperature. For us as riders, it means that when the effective temperature of the outside air, or the sun on our skin, is more than our body temperature, heat will flow from the hotter system (outside) to the cooler one (our bodies). That’s why we don’t remove clothes on very hot days.

Our body regulates its temperature through a process called thermoregulation. When the body is too hot, our central nervous system sends signals to the hypothalamus in our brain, which acts as a thermostat, to keep our body temperature at approximately 98.6º F/37.5º C. On a hot day, the hypothalamus triggers sweating and vasodilation. Here I’ll paraphrase scientificamerican.com because they’ve said it so succinctly: Sweating is a life-saving strategy the body uses to cool itself down and maintain its temperature. Without it, the body cannot regulate its temperature, which can cause overheating and hyperthermia (i.e., when the body temperature rises to a dangerous level). Turning sweat from its liquid state into a gas requires energy, taking heat from our body and resulting in the desired cooling effect. This is evaporative cooling. But, high humidity can negatively affect our body’s ability to use evaporative cooling because the air is already saturated. On humid days, lower temperatures than you’d expect can cause heat illness.

Our body is like a motorcycle

Imagine your liquid-cooled motorcycle engine running out of coolant. It will overheat and fail to function. Our bodies are the same. Too much sweating, and we dehydrate (run out of our coolant, i.e., sweat) and get sick. A rider asked me how often I take breaks to ensure I don’t get cramps while riding. He failed to understand that cramps are caused by dehydration and are the first indication that you’re running short of water. Rehydrating throughout the day is essential. The best thing for rehydration is water or water with 1 teaspoon of salt per litre. Some sports drinks are okay. Sodas with high sugars take longer to process and don’t work as well. Coffee is a diuretic, so it isn’t a good choice. Alcohol is absolutely taboo, as it can make things worse.

Dehydration causes all sorts of problems. When we are dehydrated, fluids can be drawn from our blood, reducing its volume, making it thicker, causing it to be harder to pump, and increasing our heart rate. 

The hypothalamus also triggers vasodilation that opens the blood vessels to allow more blood to flow to the skin, where heat can be lost to the air. But, when we’re dehydrated, the reduced blood volume can trigger the brain to inhibit vasodilation, hindering one of the crucial cooling mechanisms for our body. Houston, we have a problem!

If there is one key message, it is: STAY HYDRATED!

If you don’t pay attention to the signs, 

you can go from needing water to needing EMS

When exposed to high temperatures for an extended time, our body’s cooling mechanism can become ineffective, and we can succumb to heat exposure illness. If ignored, the level of severity increases. If you get a headache or feel heat cramps, stop and deal with it right away. 

The illnesses below indicate your body is not keeping up with the heat. In order of increasing severity, they are:

Heat cramps: pain caused by involuntary muscle contraction, often accompanied by thirst and a headache. They are a sign that you need to drink some water. 

Heat syncope: dizziness followed by fainting. It goes without saying that fainting while you’re riding won’t lead to a great outcome.

Heat exhaustion: pale, cool, clammy skin; weak, rapid pulse; rapid, shallow breathing; headache; nausea; and profuse sweating. The body temperature is usually in the normal range but may be low. This is starting to get serious. Hydrate and get someplace cooler.

Heat stroke: hot, dry, flushed skin; rapid onset of symptoms; muscle twitching or convulsions; dilated pupils; a body temperature above 104º F/40º C; a progressively decreased level of consciousness; the pulse may become slower; and breathing may become shallow. Heat stroke is life-threatening: CALL EMS.

Riders at higher risk include those over 50, overweight or have lung, heart or other health conditions. Alcohol and prescription drugs can also affect our ability to cool.

14 tips to keep you safe in hot weather

When riding during the dog days of summer, it is not about looking cool; it’s about staying cool. Here’s how.

Wear appropriate hot-weather clothing. Lighter colours work better. Except in really high heat (greater than 95º F/35º C), mesh jackets and pants can work well.
Always be alert and know the signs of heat illness. It doesn’t have to be as hot as you might think. When it is humid, the evaporation process that cools us is less effective. You can be at risk when the temperature is as low as 70º F/21º C if the humidity is more than 70 per cent.
Even on cooler days, the wind hitting us can wick away moisture at an alarming rate causing us to become dehydrated. You need to hydrate in almost all weather.
Stay hydrated by taking more frequent breaks or by drinking along the way. I use a Camelbak water bladder backpack. 
Keep your skin covered. Because heat is spontaneously transferred from hotter to cooler substances/systems (recall our titbit from the second law of thermodynamics) when the temperature outside is higher than our temperature, the air doesn’t cool us down; it makes us hotter. There is a reason people in the middle east stay covered.
Consider adding a cooling vest and a cooling dickie to your hot-weather riding gear. These work well if you have a mesh outer jacket.
Keep a first aid kit, extra water, and some salt as a part of your kit.
Have a first aid guide that includes the treatment for heat illness on hand. 
Find a place to have a swim. (Maybe the most fun way to cool down.)
If you’re riding in a remote area, have at least one locator beacon for the group in case there isn’t cell service.
Beware of peer pressure in the group that may make a rider hesitant to say they need a break when others are charging on.
Use comms in the group.
Take immediate action if a rider is showing signs of heat illness, especially heat stroke.
Avoid riding during the hottest part of the day.

I didn’t use to enjoy riding on high-temperature days. But that was because I lacked the knowledge and gear to ensure I’d stay cool, alert, and able to recognize the onset of heat illness. Since then, I’ve learned that riding in extreme temperatures can be safe and enjoyable if I wear the right gear and take the necessary precautions.

Get out there, ride safe, be seen, and stay cool.

– John Lewis