Exercising in warm weather can make your body stronger and more resilient—but it also carries real risks. With another record-breaking summer ahead, many people are wondering: When does it get too hot to safely work out outdoors?
Why Working Out in the Heat Is Tough on Your Body
“When it’s hot out, your heart takes longer to return to its normal rate after exercise,” explains Bethany Stillwaggon, a master coach at Row House. The more you sweat, the more water and electrolytes you lose—and that can quickly lead to headaches, dizziness, cramps, fatigue, and muscle weakness.
Your muscles need water and steady blood flow to recover and rebuild after a workout. When you’re dehydrated, that recovery process slows down because your body is struggling to deliver enough oxygen and nutrients to those muscles.
Training Your Body to Handle the Heat
It is possible to get better at exercising in hot conditions. “The better we are at regulating heat, the more effective our workouts can be,” says Ally McKinney, a personal trainer at Gold’s Gym. Like any other type of stress, your body can gradually adapt if you build intensity over time.
Still, there’s a limit. Even the most conditioned athletes can’t overcome extreme heat once it surpasses what the body can safely handle.
So… How Hot Is Too Hot?
Everyone tolerates heat differently, but once the temperature climbs past 90°F (32°C), you need to be careful. “Exercising in temperatures above 91.4°F (33°C) increases the risk of heat exhaustion,” says Milton. This happens when your body can’t keep blood flowing properly to both your organs and your skin to cool you down.
Symptoms include fatigue, fainting, or being unable to continue your workout. When temps reach 92°F (33°C), your internal temperature can climb as high as 105°F (40.5°C)—a dangerous range where heatstroke can occur.
“Heatstroke is even more serious,” Milton warns. “It causes confusion, dizziness, and collapse, and needs immediate cooling.”
Staying Safe: How to Prepare for Hot-Weather Workouts
Your best defense? Hydration.
“Before exercise, drink two glasses of water,” advises cardiologist Dr. Jennifer Haythe. “During your workout, sip four to six ounces every 20 minutes, and drink again afterward.”
Because you lose sodium through sweat, you’ll also want to replenish electrolytes. Choose drinks that provide around 14g of carbs, 28mg of potassium, and 100mg of sodium per 8 ounces, or eat foods like bananas, beets, olives, and cottage cheese.
A good rule of thumb: for every pound of weight lost through sweat, replace it with at least half a liter of water—and on hot days, you might need up to 20% more fluids than usual.
Whenever possible, schedule workouts early in the morning or later in the evening, when temperatures are cooler. If it’s blazing hot, move your training indoors.
Do Elliptical Workouts Count as Steps?
Let’s say you’ve set a goal of hitting 10,000 steps a day. Between walking your dog and running errands, you’re getting close—but what about that 30-minute elliptical session? Does it count?
Fitness experts say yes, those strides absolutely count. The elliptical gets your muscles moving and your heart pumping just like walking does—it’s just a lower-impact, more concentrated workout.
If your fitness tracker doesn’t record elliptical strides automatically, you can estimate them: count your strides for one minute, then multiply by your total workout time. Some machines even show a stride or rep count on the screen.
Keep in mind that increasing resistance or stride length may mean fewer “steps,” but it also makes your workout tougher and more effective. Remember, step counts are just one measure of activity. The most balanced fitness routine combines both everyday movement (like walking) and intentional exercise (like cardio and strength training).
As trainer Selman puts it: “In a perfect world, you’d get your steps and your workout. But if you trade a few steps for a heart-pumping session on the elliptical, that’s still a win for your health.”
1. Can the body adapt to exercising in the heat?
It actually can. If you slowly build up your workouts in the heat, your body learns how to handle it better. Over time, you get more efficient at cooling yourself down. Still, there’s a limit—once it gets too hot, even people in great shape can’t safely push through it.
2. At what temperature does exercising become dangerous?
Once it hits around 90°F (32°C), you really need to be careful. Anything above that raises your risk of heat exhaustion. When it gets to about 92°F (33°C) or higher, your body temperature can climb way too high, which can lead to heatstroke—that’s when it becomes dangerous and even life-threatening.
3. What are the best ways to stay safe while exercising in hot weather?
The key is staying hydrated. Drink plenty of water before, during, and after your workout, and make sure you’re also getting electrolytes—either through a sports drink or foods like bananas, olives, or beets. Try to work out early in the morning or later in the evening when it’s cooler. And if it’s just too hot, it’s totally fine to move your workout indoors. Safety comes first.
