Words: Avery Stonich
Illustrations: Kyle Stecker
You’ve been huffing up a hill for more than an hour, admiring the view to distract you from leg cramps. “Why is this so hard today?” you wonder. You reach down to take a swig and realize you’re out of water. To top it off, you’re slightly hungover from a raucous party the night before, and you feel slightly nauseous. Then you notice you’re not sweating. “That’s odd…”
It can kill you or cause severe organ damage. If you think it afflicts only sick or elderly people baking in a Chicago heat wave, think again. Exertion can bring on heatstroke in anyone. Knowing its symptoms, how to prevent it, and how to treat it is key for anyone who rides in hot temperatures.
Technically speaking, heatstroke is hyperthermia, when body temperature rises above 104 degrees F. It often starts with cramping and sweating, then progresses to exhaustion that is out of proportion to the level of exertion. Left untreated, a full-blown case of heatstroke starts shutting down vital functions.
Dr. Tim Meyers, emergency room director at Boulder Community Hospital in the active Colorado town, says they see a handful of cases each year, usually in young, healthy people. “The heatstroke cases we see tend to be athletes who are participating in triathlons that take place here in the summer,” said Dr. Meyers.
Exertional heatstroke can result from overdoing it in hot temperatures coupled with dehydration. High humidity increases the chances of heatstroke, as do certain medications—including beta blockers, diuretics, antidepressants and stimulants. Some people’s genetic wiring simply makes them less effective coolers.
Suspect you have heatstroke if you have been riding in the heat and you get off your bike and can’t catch your breath in a normal amount of time. Lethargy, dizziness, nausea and lack of sweating are other warning signs. In extreme cases, people stop needing to pee, have severe stomach pain, and experience seizures.
For cases requiring medical care, treatment includes checking vital signs, assessing kidney and liver function, IV rehydration, and instituting a “rapid cooling protocol.” “We’ll get a person naked, soak them in water, bring in high-speed fans, and sometimes put a catheter in the patient’s groin to remove blood, cool it, and return it to the body,” said Dr. Meyers. For some, this treatment suffices. For others, hospitalization is necessary—when a patient shows signs of kidney failure, has a seizure and can’t breathe properly, or—in the worst cases—suffers from full cardiovascular collapse.
“The challenge with heatstroke is that it can masquerade as other things, so it’s hard to pinpoint. That’s what makes it a scary diagnosis,” said Dr. Meyers. “It can happen to people who have been active before. And the symptoms can be subtle when they start to present. Sometimes it progresses before it really declares itself.”
The first step is awareness. Tune into your body. When you’re biking in hot temperatures, pay attention to symptoms that are different. Perhaps you feel more tired than usual, or you have uncharacteristic muscle or abdominal pain. If you suspect you might be developing heatstroke, stop exercising immediately and take steps to cool yourself.
Cyclists have one advantage: the bike. If you’ve been grunting up a hill and overheating, consider turning around and using conductive cooling (i.e., rushing air) on the downhill to cool off faster than you would sitting on hot asphalt.
The best approach is to avoid heatstroke in the first place. Common sense prevails. Wear light clothing. Stay hydrated. Don’t charge too hard in the heat of the day. And if you’re super hungover on a hot July day, maybe it’s best to stay home.
What to do if you suspect you have heatstroke
- Try to cool down—seek shade, take off excess clothing, dunk in a river or lake.
- Drink water.
- Fan yourself and spray mist or pour water on your body.
- Pack your body in ice. Focus on armpits, groin, neck and back. Substitute snow if you’re on a ride in the mountains.
- If you’re camping, send someone back to camp to grab ice and cold water.
- Assess the severity of the symptoms and call for help if necessary.
- Take your temperature if you can. If it’s over 104°, seek medical attention immediately.