- Be Alert: Running in the heat of summer can be dangerous if proper precautions and preparations are not followed.
- Avoid dehydration: You can lose between 6 and 12 oz. of fluid for every 20 minutes of running, espeically when it's hot out.
- Prehydrate: Drink 10–15 oz. of water 10 to 15 minutes prior to running, and drink water every 20–30 minutes during your run.
- Carry water: Bring water with you on the run and plan your route for long runs (over 60 minutes) to be able to refill your water bottle as needed.
- Understand heat index dangers: Avoid running outside if the heat is above 98.6 degrees and the humidity is above 70-80%. If the humidity in the air is so high that it prevents the process of evaporation of sweat from the skin, you can quickly overheat and literally cook your insides from an elevated body temperature.
- Know the signs of heat illness: If you become dizzy, nauseated, have the chills, or cease to sweat…. STOP RUNNING! Find shade, drink water, and ff you do not feel better, get home or call for help.
- Know the signs of heat stroke: Symptoms of heatstroke include mental changes, such as confusion, delirium, or unconsciousness, and skin that is red, hot, and dry, even under the armpits.
- Get help immediately if you suffer heat stroke: Heatstroke is a life-threatening medical emergency, requiring emergency medical treatment. Call 911.
- Check with your doctor: If you have heart or respiratory problems or you are on any medications as these can impact your ability to tolerate heat while exercising.
- Dress for the weather: Wear light colored, breathable fabrics. Avoid long sleeves and long pants. Never wear a sweat suit in high heat in an effort to lose water weight...see above about the dangers of heat stroke.
- Apply sunscreen: 15spf or more can help protect your skin from sunburns. Having 5 or more sunburns doubles your risk for melanoma (skincancer.org)
Watch the Weather
High temperatures combined with humidity can create unsafe running conditions. Closely monitor both the air temperature and relative humidity and know the average ranges for your geographic area. The Wet Bulb Globe Temperature (WBGT) index is widely used by athletic organizations, the US military, OSHA and others to measure the safety of outdoor conditions. It’s a combined measurement of the air temperature, relative humidity, sun, and wind and can be estimated using an online calculator. Alternatively, you may consider using the Heat Index, which measures heat and humidity in the shade for adults.
We recommend following the Regional Heat Safety Threshold for Athletics in the US. The chart below outlines WBGT ranges for three categories of US geographic classifications (see map), and the recommended activity modification guidelines.
Know the Signs of Heat Exhaustion & Stroke
