Why Does My Face Turn Red When I Exercise?

Dear Fit,
I've been running outside since the Spring, but now that it's in the 80s here, [and] when I get back from my run, my face looks unnaturally bright red. It really scared me when I caught a glimpse of myself in our front hall mirror. I feel OK during and after my run, but is this bad for me? Is this a sign that I'm dehydrated or working too hard? I don't want to give up my outdoor runs because I'm training for a half marathon in the Fall and I can't afford a gym membership or treadmill. Thanks for your help!
—Red Hot and Bothered

I'm fair-skinned so I can totally relate to the postworkout beet-red face. I've even had people stop me while walking home from my run to ask if I was OK. I guess it can be kind of scary to see someone all sweaty and abnormally flushed. Keep reading to find out what causes it and if it's reason to worry.

Your frighteningly scarlet skin may not look the prettiest, but it's no cause for alarm. It's actually just a sign that you're working hard and building up heat. When your body temperature begins to climb, your smart little body perspires to keep itself cool, but it also dilates the blood vessels in your skin to reduce your overall body temperature. Your face turns bright red because warm, oxygenated blood rushes to the surface of your skin, which helps heat radiate off it and prevents you from overheating.

You can continue running outside as long as you feel good and have no other symptoms. If you find that your flushed face is accompanied by fatigue, dizziness, sweating more than usual, or nausea, then it could be a sign of heat exhaustion. You said you're running in 80-degree temps, so you should be aware that working out in the Summer heat is definitely a risk. If you're experiencing these symptoms, stop running immediately, get inside where it's cooler, loosen up tight clothing (or remove it all together), and drink plenty of cool water.

To prevent heat exhaustion, make sure you're drinking plenty of fluids before and during your workout, and try to run during a time of day when temperatures are the lowest, like in the early morning. It also helps to run on shady woods trails or on a breezy path near a lake or beach.