All winter long, you probably dreamt of the summertime and the joy of exercising outside. The problem? The heat of summer puts added stress on your body. With temperatures reaching the 80s, 90s, and sometimes higher, your heart can face some serious strain when you exert yourself outside. Your body uses two processes in order to deal with the extra heat: radiation and evaporation, both of which require the heart to work harder.

Heat naturally moves from warm areas to cooler ones. If the air around you is cooler than your body, you radiate that heat into the air. But when the air temperature is close to your body temperature, this transfer stops. To keep your skin cool, your body reroutes blood flow, making your heart beat faster and pump harder; this process is called radiation.

Sweating excessively during your workout can be a bother, but each bead of sweat that evaporates from your skin expels heat from your body. On dry days, this process of evaporation can successfully cool your bloodstream, helping to ease the strain on your heart. But as the humidity creeps higher (as it tends to do here in Pittsburgh), the amount of water vapor in the air makes evaporation more difficult, straining your cardiovascular system.

Still ready to get outside in the summer sun? Follow these heart-conscious tips for running in the hot weather:

  1. Time It Wisely: Try getting your run in before noon or after 4:00 pm, when the temperatures are the lowest.
  2. Drink Up: As always, be sure to stay hydrated with water and drinks containing electrolytes.
  3. Dress Properly: Of course it’s smart to wear lightweight clothing, but also try to wear light-colored clothing. The lighter color will reflect heat and sunlight, which will help keep your body cool.
  4. Slow Down: Since you heart will be working extra hard, be vigilant to regularly check your heart rate. Listen to your body and slow down when you need to. You can also try using a wearable fitness device (like FitBit) to monitor your heart rate.
  5. Know When To Stay Inside: If you find it difficult to breathe after just walking outside, chances are it’s not a good time to work out in the great outdoors. The experts at WebMD advise that you avoid exercising outside in temperatures above 90 degrees.

The summer heat is something to keep in mind when exercising outdoors, but it does not mean the end of summer enjoyment! Enjoy your workouts by staying safe and being heart conscious.