This thirst sensitivity is decreased further after the age of 60. Evaporation is further enhanced when you allow as much skin as possible to be exposed to the air. Your chances of a heat condition increase if you are wearing clothing that is impermeable to water. Shorts and tank tops, with proper sunscreen, are good choices. However, caution still must be taken in highly humid conditions.
Relative humidity is, essentially, a measurement of the amount of moisture in the air.
If the air is saturated with water our bodies will have greater difficulty trying to evaporate sweat. Exercise should be avoided when both the temperature and humidity reach excessive levels. Initially, you will need to cut back on the intensity and duration of your exercise if you are used to working out indoors. Give yourself 7 to 10 days to become acclimated to the heat by exercising at lower intensities for shorter durations and gradually increasing both over time. You should also attempt to exercise in the cooler parts of the day to help minimize the heat you'll pick up from the sun and roadways.