What Temperature Is Too Hot for Cycling

Dehydration and overheating are both risks when you’re trying to get some miles under your tires. Your sun exposure can make this risk even more dangerous. Other factors, such as the humidity level and wind speed can have a big impact.

Hard and Fast Rules

If it’s over 100 degrees Fahrenheit, it’s too hot for everyone. If it’s over 90 degrees Fahrenheit, it may be too hot for you. Everyone has their own tolerance, particularly if you have no shade breaks on your ride. Regardless, make sure you always have water.

Pre-Hydrate

Drinking water while riding a bike takes some coordination. You may also not notice that you’re getting dehydrated until you’re suddenly in trouble. You can reduce the risk of dehydration by pre-hydrating.

Don’t focus just on your comfort level. You may be perspiring and the breeze may be cool, but you’re still losing fluids and warming up. You will need water before you know you need water; catching up after getting dehydrated can take days.

Acclimate

If you want to get more comfortable riding in the heat, learn to live in the heat. Don’t cool your home to 70 degrees in the summertime if you want to be ready to ride in 90-degree weather. Bump up your thermostat to train your body to tolerate warmer temps and hydrate accordingly.

Pack Smart

As you pack up, make room and space for water. Know your route and plan to stop and pick up more water on a longer trip. Wear a jacket to start, especially if you’re riding early in the day, to maintain your level of acclimation. When you stop for water, lose the jacket. The next time you stop for water, douse yourself to let the cooling power of air on wet fabric reduce your body temperature.

Plan ahead. Fill small water bottles 2/3 full and freeze them the night before so you can use them as small blocks of ice to keep your liquid water cool and comfy. If you find yourself overheating on the road, you can tuck these frozen bottles against your navel to calm your core down as you hydrate. Use a timer and remove the bottle after 10 minutes. Frostbite hurts, and frostbite on your navel will be miserable.

Electrolytes and Sugar

If you’re not crazy about freezing water bottles, treat yourself to electrolyte popsicles for your halfway break. Yes, they contain a little sugar. However, they can be easier to savor so you don’t feel overloaded on sweetness. Of course, follow up your popsicle with plain water.

Once you’re on the trail, look for shade and park when you can. If your shade stop becomes your turnaround spot, so be it. Even if you ride early, the day may warm up quickly, particularly if the humidity is high.

Check the Weather

The warmer the air, the more water it will hold. If you generally ride in dry conditions and the rainy season hits, your cooling tricks may not work. For example, in 30% humidity, dousing yourself with water of any temperature will cool your body because wicking moisture is a cooling mechanism. If the humidity is 70%, dousing yourself with warm water means you’re just riding in a private swamp.

Pulse Points

If you’re on a ride and notice that you or a fellow rider is showing signs of dehydration like cramping, weaving or having balance problems, or nauseated, you need to stop, preferably in shade. Focus on pulse points, particularly the

neck
wrist and ankle
knees, elbows and armpits

Place a cool, wet cloth around their neck and encourage them to drink water. Get their shoes off and let their feet and ankles cool off. Run or wrap cool wet cloths around ankles and wrists. If they are bright red, no longer sweating, or not making sense, call 911.

When cooling pulse points, do make sure you don’t apply ice cold water to their body, particularly their head or neck. The headache from over-cooling the head and neck is extremely painful.

Know Your Terrain

If you’re headed out for a brand new ride, don’t go on a hot day. If possible, scout out new rides early in the day. Pumping hard on a new trail will raise your perspiration and your body temperature. If you get hot on the way up a tough trail and find no shade at the top, you may be in serious trouble.

Sunrise, Sunset

Early morning is the coolest time of the day. While evening rides mean less sun exposure, the air will be warmer. If you can only ride in the evening, plan to take flat routes in the evening. If you can get out at sunrise, you can push harder without overheating.

Of course, both of these times of day mean reduced visibility. Gear up accordingly so you are seen if you need to ride on trails that run beside motorized vehicles.

Pre-hydrate before every ride. Always carry water, and consider carrying an electrolyte supplement if you know you’ll be out in high temps for long stretches. Be ready to douse yourself if you’ll be riding in full sun. Acclimate as possible, turn around if you get overheated, and call 911 if you get confused or can’t keep water down.