Heat Index Calculator

Air temperature outside is not the only factor associated with the potential for heat injury or illness. Humidity also plays a major role. The higher the relative humidity, the less your sweat can evaporate -- which is an important way your body cools itself.

• 80 to 90 Degrees - Fatigue is possible with prolonged exposure and/or physical activity.  
• 90 to 105 Degrees - Sunstroke, heat cramps, and heat exhaustion possible with prolonged exposure and/or physical activity.  
• 105 to 130 Degrees - Sunstroke, heat cramps or heat exhaustion likely, and heatstroke possible with prolonged exposure and/or physical activity.  
• 130 degrees and higher - Heatstroke/sunstroke highly likely with continued exposure.