Understanding the Risks of Running in the Heat 

Many of these great tips were taken out of an article by author Amanda Brooks, 6/8/2023 / Run to the Finish

Summer is truly the perfect time to get outside and enjoy the sunshine, but before you head out on your run, it’s important to understand the risks of running in high temperatures.

While running is an excellent way to stay healthy and active, running in the heat can cause dehydration, heat exhaustion, and heatstroke.

Dehydration is a common risk of running in the heat. When you run, your core body temperature rises, and you start to sweat. Sweating is your body’s way of cooling down, but it also causes you to lose fluids rapidly.

If you don’t replace those fluids, you can quickly become dehydrated. Symptoms of dehydration include dry mouth, thirst, headache, muscle weakness, and fatigue.

If left unchecked, dehydration can lead to heat exhaustion. Heat exhaustion is a more severe form of dehydration and can result in muscle cramps, dizziness, nausea, and in severe cases, loss of consciousness. Heat exhaustion is a serious condition and requires immediate medical attention.

If you feel dizziness or nausea then STOP. You don’t win prizes for hurting yourself. These are early signs of heat exhaustion and should not be ignored.

Also know that people react different to heat. It may bother you more or less than other runners. If possible,  resorting to a training on the treadmill when the heat is overwhelming can  a safer option. Not a daily recommendation, but one that should be considered when air quality is unsafe.

Heat Stroke and Sunburn

Heatstroke is the most severe form of heat-related illness. It occurs when your body temperature rises to dangerous levels, and you no longer can regulate your temperature. Heatstroke is a medical emergency and can be life-threatening.

Symptoms of heatstroke include high body temperature, confusion, disorientation, and loss of consciousness.

Sunburn is another common risk of running in the heat. Sunburn can cause pain, blistering, and long-term skin damage. When you’re running in the heat, it’s essential to protect your skin by wearing sunscreen, a hat, and sunglasses.

It’s also important to pay attention to the time of day when you’re running. Running in the early morning or late evening when temperatures are cooler can reduce your risk of heat-related illnesses. Plus, it’s crucial to stay hydrated by drinking plenty of fluids before, during, and after your run.

How to Prepare for Running in the Heat

Over a period of a few weeks your body will begin to adapt to running in the warmer temperatures while that adaptation is happening, there are a few things you can do to help.

For the first few weeks that you start running in warmer weather, take it slow and just listen to your body. It will better adapt to the temperature, but it’s still going to feel harder running in high temps and high humidity.

Choosing the Right Time of Day

While running anytime during the day is better than not running at all, it’s best to avoid running during the hottest part of the day, which is typically between 11 a.m. and 3 p.m.

If possible, plan your run for early morning or very late afternoon/early evening  when temperatures are cooler. This will not only make your run more comfortable, but it will also reduce your risk of heat exhaustion or heat stroke.

Hydrate Properly

Staying hydrated before, during, and after your run is absolutely essential in preventing dehydration.

Aim to drink 16-20 ounces of water , but also sports drinks like Gatorade because of the need to replace electrolytes at least 30 minutes before heading out on your run, and carry a water bottle or hydration pack with you during your run to stay hydrated.

Plus, incorporating fruits and vegetables high in water content, such as watermelon and cucumbers, can help boost your hydration level.


Dressing Appropriately for the Heat

When it comes to dressing for your run, it’s important to choose clothing that will keep you comfortable and cool throughout. I recommend going for lightweight and breathable clothing since they can help keep you cool during your run.

Choose moisture-wicking fabrics that will pull sweat away from your body, allowing you to stay dry and comfortable. Or if you prefer to run without a shirt go for it, we want to help get the sweat off your skin. This allows your body to better cool itself.

Plus, a hat and sunglasses  can help protect your face and eyes from the sun’s rays.

It’s also important to protect your skin from the sun’s harmful UV rays.  

Pace Yourself

Running in the heat requires you to adjust your pace and expectations. It’s best to slow down and take it easy when running in high temperatures to avoid overexertion and heat-related illness.

These are not the times to be doing some of your hardest workouts.  

When you run in the heat, your body has to work harder to regulate its temperature, which can lead to fatigue and exhaustion. By pacing yourself, you can conserve your energy and stay safe. Pace yourself by checking out the dew point adjustments I mentioned above.

It’s also important to pay attention to the time of day when you run. Try to avoid running during the hottest parts of the day, typically between 10:00 am and 4:00 pm. Instead, schedule your runs for early morning or late evening when the temperatures are cooler.

It’s important to listen to your body when running in the heat. If you experience symptoms of dehydration or heat-related illness, it’s best to stop your run and seek shade and water. Ignoring these warning signs can lead to long-term health effects.


Incorporate Walk Breaks, especially our new runners!

Incorporating walk breaks, or sticking to the run-walk-run method can help you adjust to running in the heat. Taking regular breaks can help your body regulate its temperature, prevent overheating and dehydration, and keep your energy levels up.

A good rule of thumb is to run for five to ten minutes and then take a one-minute walk break. Repeat this cycle throughout your run.

You can also use your walk breaks to hydrate. Especially when by yourself, try and bring a small  running water bottle with you on your run and take a few sips during your walk breaks. Staying hydrated is crucial when running in the heat, and drinking water regularly can help prevent dehydration and heat-related illnesses.  

Why Does it Feel Harder to Run When it’s Hot?

Is running in the heat harder?


The heat alone makes your heart rate rise, but with running in high humidity your body can’t cool down because the sweat never evaporates.

  • HR increases up to 10 beats per minute in humidity ranging from 50% to 90%
  • HR increases by 2 to 4 beats per minute in temperatures from 60°F to 75°F
  • HR increases up to 10 beats per minute in temperatures from 75°F to 90°F

It doesn’t just feel harder, it really is more work for your body. SO< USE YOU HEAD AND DO THE RIGHT THINGS:

  • Hydrate (Notice “Hydration” keeps repeating !)
  • Skin protection (sunscreen at 30 spf or higher- strongly recommend 50 spf
  • Hat, Sunglasses
  • Wear lightweight and light colored running clothes. Dark colors absorb the sunlight.
  • Phone and don’t forget to turn the RunKeeper on!

other ideas……

  • Wear a hat filled with ice or an ice bandana 
  • carrying a handheld with frozen ice water, the cold in your palm has been proven to help keep your core temperature down


LASTLY, dont let this word get in the way!

Why we need to embrace the struggle


 Don’t Forget to Smile

Seriously!! Studies have shown that smiling will make you feel better because it’s hard to have both positive and negative thoughts at the same time….plus no one is making you run!

You GET to run.