Summer is in full swing and depending on where you live temperatures could be reaching near, or even above, 100 degrees. If you live in the southeast or Midwest you also have the humidity to factor in.
Higher outside temperatures will quickly increase body temperature when exercising. Because it will take longer for the body to regulate heat, one's heart rate (HR) will also increase as a result. This will make a workout seem much harder than it did/does when exercising in cooler temps during fall/winter, or when exercising indoors with air conditioning.
There are a few tips to consider that will help to give you a safe, effective workout when exercising outdoors in the heat.
1. Keep the intensity low. No need to go out and perform intense intervals on the track. Instead go for a slow run or even a hike. Perceived exertion will be much higher than in cooler temps, so even a slow run will seem much harder.
2. Try to exercise early (5-7am) before the temps rise or later in the evening (7-9pm) when the sun is beginning to set. Another benefit to this is that if you're at a park, odds are there might not be many others.
3. Wear light colored clothing and a hat with vents and sunscreen. White shirts/hats will reflect the sun better than dark colored clothing, and sunscreen will protect your skin.
4. Drink lots of fluids...16 oz 1 hour before, 8-10 oz every 15 min during, and 8-16 oz immediately after exercising. In humid climates your body will sweat more. Because of this it is important to replace that loss of fluids with electrolytes (i.e.: Gatorade, Nuun tablets) to prevent excessive cramping
5. Be smart! If you start to feel disoriented or start to have blurred vision, end the workout immediately. Or if you have access, cool down and then head indoors to finish the workout. With higher temperatures, heat exhaustion and even heat stroke become more common during exercise.
Exercising outdoors in extreme heat can still be fun, just make sure to use common sense and a few of these tips above. My best advice in extreme heat is to exercise indoors...in a controlled air conditioned environment.