When you ride long distances in intense, summer heat (say, on your way to Sturgis or Daytona) dehydration, heat exhaustion, and heatstroke can sneak up on you before you’re aware of what’s happening.
So, it pays to know the warning signs, how to react when you experience them, and, most importantly, how to prevent them from happening in the first place.
The human body has a remarkable thermoregulation system. Under most circumstances, it does a great job of keeping your innards at an ideal 98.6 degrees Fahrenheit. Not 98, not 99; 98.6. When things outside your body get too hot or too cold, it has ways to accommodate.
Understanding how to cool your body properly starts with understanding how it maintains such a consistent inner temperature. You might wonder: If our body temperature is 98.6 degrees, why are we so comfortable at “room temperature”? Simply put, it’s because the chemical reactions occurring inside your body are continuously producing heat, which must be dissipated. At 70 or so degrees, wearing a modest amount of clothing, your body sheds heat at the same rate it produces it.
When you start moving around, your body generates more heat. You start to feel warm as your body tries to cool down. The same thing happens when the ambient temperature goes up. If the air conditioner breaks, and the room temperature rises to, say, 85 degrees, your skin doesn’t cool as effectively, so your body finds other ways to shed the excess heat.
The first thing it does is sweat. Glands in the skin secrete moisture, which draws heat from the body through evaporation. That’s why the phrase “it’s a dry heat” really does have meaning. In the desert, this process works quite efficiently. Sweat evaporates from your skin before you even know it’s there, taking excess heat with it. If you find yourself thinking, “I’m not even sweating!” – you are, you just don’t feel it.
In more humid environments, your body sweats, but the air is already so moist it can’t evaporate easily. And if it can’t evaporate, it can’t do its job. The sweat stays on your body, along with the heat, making you feel hot, sticky, and uncomfortable.
Your body is also cooled through “convection.” Scientifically speaking, this means the removal of heat through the circulation of air. Motorcycle-ly speaking, this is that wind-in-your-face feeling we all love. And in the heat, the wind can be a lifesaver.
One of the most common mistakes of riding in the heat is thinking that exposing more
skin by wearing less clothing will help you cool off. And while riding in a T-shirt or tank top may help you feel a little cooler in the short run, it’s bad practice for the long haul.
For starters – and this may seem obvious – more exposed skin puts you at greater risk for painful sunburn. And let’s face it: While it works for some people, not all of us are in a hurry to sport that “grizzled biker” look!
The risks presented by sun exposure can, of course, be reduced by liberal application of a quality sunscreen. And even if you’re wearing full riding gear, be sure not to overlook places like the back of your neck, your face, the backs of your hands, and your throat.
Do the sleeves of your riding jacket ride up at all when you reach for the handlebars? If so, check and make sure that the sliver of bare wrist between your sleeve and glove isn’t taken for granted.
When you ride in the heat – particularly when you go without a fairing or windshield – the wind in your face draws moisture from exposed skin, even as it provides a cooling sensation. This helps deplete your body’s water supply. The old axiom “Drink before you feel thirsty” certainly holds true on a motorcycle trip.
A good rule of thumb is to drink at least eight ounces of water every hour while you’re riding in the heat – a full pint, 16 ounces, would be even better. Plain water is best, but sports drinks are a good option. However, since you’re not burning a lot of calories on your motorcycle (unlike those triathletes), replacing your electrolytes and “refueling” are not as critical. Plain old H2O is what your body needs most.
When your body starts to run low on fluids, it loses some of its ability to cool itself through the evaporation of sweat, and a process called “vasodilation” begins. This simply means that the blood vessels near your skin get larger, resulting in increased blood flow closer to the surface, which helps dissipate heat. The problem is, this results in decreased blood flow to other important body parts, such as your muscles and your brain.
With that in mind, if you start feeling a little weary, hang out in the air conditioning for a while; it’s best not to hurry when the heat’s on. And be alert for other signs of heat stress. According to cdc.gov, these can include:
If you start to experience any of these, get off the road, find some shade (or air-conditioning), and plenty of water. Drink it. Pour it on your head and neck. Do whatever you can to lower your core temperature. Lie down if you need to and elevate your feet to help increase blood flow to your brain.
Let’s say your plan for the day is a 500- mile ride across the desert. Your first heat-fighting measure is to start early, when it’s cooler. In fact, you may even need to bundle up a little to start; it can get really chilly overnight in the desert.
Dress in layers that can be shed easily as things heat up. Ideally, the layer next to your skin should be a breathable synthetic that will draw moisture from your skin. A long-sleeve (more on that in a moment) synthetic tee is a great choice. Layer up from there, as needed. If it’s nice and chilly, a top layer that breaks the wind may be necessary. In warm weather, a mesh jacket over-layered with a rain jacket in cooler morning air works well.
Now, as the temperature rises throughout the day, you can shed layers as needed.
But don’t take off too much. In blazing heat, it may be tempting to strip down to your T-shirt or less, but covering up can actually help you stay cool.
For starters, exposed skin dries out very quickly in the sun and wind. Yes, this can help with the cooling effect, but it also makes it harder to keep your body hydrated. Keeping your arms covered (remember that synthetic long-sleeve T-shirt) helps reflect the heat of the sun, prevents sunburn, and helps keep your sweat from evaporating too quickly.
Beyond the mesh jacket and long-sleeve T-shirt, other motorcycle gear choices can help you keep cool. Something as simple as a wet bandana around your neck or under your helmet can do wonders. Soaking your T-shirt helps a lot. If you ride in high temperatures frequently, consider investing in a “hydration vest” lined with crystals that absorb and hold water to keep you cool while you ride.
Many of the newer Harley-Davidson® Touring models have vents that open and close, allowing you to control the amount of air that flows across your body. Many full-face helmets also have adjustable vents.
Remember, both you and your Harley® motorcycle are air-cooled. When you’re stuck in traffic, the air flow stops. If it looks like a long delay, sometimes it’s best to get off the road and wait it out. And make sure to keep up with your oil changes to protect your engine.
Finally, don’t forget to use sunscreen on any exposed skin, especially covering spots like the back of your neck, the backs of your hands, or that little gap you might have between your gloves and the ends of your sleeves.
Your body does a great job of cooling itself. With a little help, it can do even better. And make the hottest rides safer and more comfortable.
A version of this post appeared in HOG® magazine.