Severe Weather Awareness: Extreme Heat

The final topic to highlight during Severe Weather Awareness Week in Minnesota is Extreme Heat.  The Minnesota Department of Public Safety says heat-related fatalities outpace deaths in several other weather categories combined.  Based on a national average from 1992-2001, excessive heat claimed 219 lives on average each year.

By contrast, floods killed 88, tornadoes 57, lightning 52 and hurricanes 15 during that period of time.  An excessive heat watch is issued when the heat index is expected to be greater than 105 degrees Fahrenheit and nighttime low temperature will be at least 75 degrees Fahrenheit or higher two consecutive days.  An execessive heat warning is issued within 12 hours of the heat index reaching one of two levels.  A warning will be issued if the index is greater than 105 degrees for any period of time.

The heat index is a measure of how hot it feels when relative humidity is added to the air temperature.  Heat index values are based on shady conditions with a light wind; exposure to full sunshine can increase by up to 15 degrees.

Heat problems can include heat cramps, heat exhaustion and heat stroke.

Heat cramps are muscular pains and spasms that usually occur in the legs or abdomen caused by exposure to high heat and humidity, and loss of fluids and electrolytes.  It is recommended you find a cool location to rest and take fluids (water or sports drinks).

Heat exhaustion typically involves the loss of body fluids through heavy sweating during strenuous exercise or physical labor in high heat and humidity.  Signs of heat exhaustion include cool, moist, pale or flushed skin, heavy sweating, headache, nausea, dizziness, weakness and exhaustion.

Heat stroke (also called sunstroke) is a life-threatening condition in which a person's temperature control system stops working and the body is unable to cool itself.  Signs of heat stroke include hot, red skin which may be dry or moist, changes in consciousness, vomiting and high body temperature.

Heat stroke is life-threatening.  Call 9-1-1 immediately.

During a heat wave the Minnesota Department of Public Safety suggests we need to drink more fluids but avoid alcohol and high-sugared drinks because they tend to add to dehydration.

Stay in an air-conditioned place during the hottest parts of the day.  If air conditioning is not available, be in a location with adequate shade, air-flow and ventilation.

Make use of public venues with air conditioning like a public library, local mall or other facility.

Remember to wear light colored clothing that's lightweight and loose-fitted and remember to never leave a person or animal in a closed, parked vehicle.