Preparing for Extreme Heat

With the potential for a few hot summer days the Yale University Office of Emergency Management would like to take this opportunity to alert you to precautions and steps to take to stay healthy during prolonged periods of high temperatures.

Heat kills by pushing the human body beyond its limits. In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to maintain a normal temperature.

Most heat disorders occur because the person has been overexposed to heat or has over-exercised for their age and physical condition. Older adults, young children and those who are sick or overweight are more likely to succumb to extreme heat.

A heat wave is an extended period of extreme heat, and is often accompanied by high humidity. These conditions can be dangerous and even life-threatening for humans who don’t take the proper precautions.

Know the Terms

Familiarize yourself with these terms to help identify an extreme heat hazard:

Heat Wave - Prolonged period of excessive heat, often combined with excessive humidity.

Heat Index - A number in degrees Fahrenheit (F) that tells how hot it feels when relative humidity is added to the air temperature. Exposure to full sunshine can increase the heat index by 15 degrees.

Heat Cramps - Muscular pains and spasms due to heavy exertion. Although heat cramps are the least severe, they are often the first signal that the body is having trouble with the heat.

Heat Exhaustion - Typically occurs when people exercise heavily or work in a hot, humid place where body fluids are lost through heavy sweating. Blood flow to the skin increases, causing blood flow to decrease to the vital organs. This results in a form of mild shock. If not treated, the victim’s condition will worsen. Body temperature will keep rising and the victim may suffer heat stroke.

Heat Stroke - A life-threatening condition. The victim’s temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly.

Sun Stroke - Another term for heat stroke.

Excessive Heat Watch - Conditions are favorable for an excessive heat event to meet or exceed local Excessive Heat Warning criteria in the next 24 to 72 hours.

Excessive Heat Warning - Heat Index values are forecast to meet or exceed locally defined warning criteria for at least 2 days (daytime highs=105-110° Fahrenheit).

Heat Advisory - Heat Index values are forecast to meet locally defined advisory criteria for 1 to 2 days (daytime highs=100-105° Fahrenheit).

For more information on how to best prepare for extreme heat and what actions to take during extreme heat please visit: http://www.ready.gov/heat.