Heat Awareness Day
May 25, 2012

This year National Heat Awareness Day is observed May 25, 2012. Heat is the number one weather-related killer in the United States, resulting in hundreds of fatalities each year.  North American summers are hot; most summers see heat waves in one or more parts of the United States. East of the Rockies, they tend to combine both high temperature and high humidity; although some of the worst heat waves have been catastrophically dry. The National Weather Service issues several heat related products as conditions warrant for Extreme Heat.
 
Excessive Heat Outlooks: Issued by the Climate Prediction Center (CPC) when the potential exists for an excessive heat event in the next 3-7 days.
 
Excessive Heat Watches: Issued by the local NWS Weather Forecast Office when conditions are favorable for an excessive heat event in the next 12 to 48 hours. A watch is used when the risk of a heat wave has increased but its occurrence and timing is still uncertain.
 
Excessive Heat Warnings/Advisories: Issued by the local NWS Weather Forecast Office when an excessive heat event is expected in the next 36 hours. These products are issued when an excessive heat event is occurring, is imminent, or has a very high probability of occuring. The warning is used for conditions posing a threat to life or property.
 

What do Forecasters look at to decide when to issue Excessive Heat Products?

NOAA's NWS heat alert procedures are based mainly on Heat Index Values. The Heat Index, sometimes referred to as the apparent temperature, is given in degrees Fahrenheit. The Heat Index is a measure of how hot it really feels when relative humidity is factored with the actual air temperatures.

To find the Heat Index temperature, look at the Heat Index Chart below:

IMPORTANT: Since heat index values were devised for shady, light wind conditions, exposure to full sunshine can increase heat index values by up to 15°F.  Also, strong winds, particularly with very hot, dry air, can be extremely hazardous.

The Heat Index Chart shaded zone above 105°F shows a level that may cause increasingly severe heat disorders with continued exposure or physical activity.
 

 The Hazards of Excessive Heat
When the body heats too quickly to cool itself safely, or when you lose too much fluid or salt through dehydration or sweating, your body temperature rises and heat-related illness may develop. Heat disorders share one common feature: the individual has been in the heat too long or exercised too much for his or her age and physical condition. 

Studies indicate that, other things being equal, the severity of heat disorders tends to increase with age. Conditions that cause heat cramps in a 17-year-old may result in heat exhaustion in someone 40 years old, and in heat stroke in a person over 60. Sunburn, with its ultraviolet radiation burns, can significantly retard the skin's ability to shed excess heat. Acclimatization has to do with adjusting sweat-salt concentrations, among other things. The idea is to lose enough water to regulate body temperature, with the least possible chemical disturbance--salt depletion.
 
SUNBURN: Redness and pain. In severe cases swelling of skin, blisters, fever, headaches. First Aid: Ointments for mild cases if blisters appear and do not break. If breaking occurs, apply dry sterile dressing. Serious, extensive cases should be seen by physician.
 
HEAT CRAMPS: Painful spasms usually in the muscles of legs and abdomen with heavy sweating. First Aid: Firm pressure on cramping muscles or gentle massage to relieve spasm. Give sips of water. If nausea occurs, discontinue water.
 
HEAT EXHAUSTION: Heavy sweating; weakness; cold, pale, clammy skin; thready pulse; fainting and vomiting but may have normal temperature. First Aid: Get victim out of sun. Once inside, the person should lay down and loosen his or her clothing. Apply cool, wet cloths. Fan or move victim to air conditioned room. Offer sips of water. If nausea occurs, discontinue water. If vomiting continues, seek immediate medical attention.
 
HEAT STROKE (or sunstroke): High body temperature (106° F or higher), hot dry skin, rapid and strong pulse, possible unconsciousness. First Aid: HEAT STROKE IS A SEVERE MEDICAL EMERGENCY. SUMMON EMERGENCY MEDICAL ASSISTANCE OR GET THE VICTIM TO A HOSPITAL IMMEDIATELY. DELAY CAN BE FATAL. While waiting for emergency assistance, move the victim to a cooler environment reduce body temperature with cold bath or sponging. Use extreme caution. Remove clothing, use fans and air conditioners. If temperature rises again, repeat process. Do NOT give fluids. Persons on salt restrictive diets should consult a physician before increasing their salt intake.
 
For more information contact your local American Red Cross Chapter. Ask to enroll in a first aid course.  
 

  Children, Adults and Pets Enclosed in Parked Vehicles are at Great Risk  

Each year, dozens of children left in parked vehicles die from hyperthermia. Hyperthermia is an acute condition that occurs when the body absorbs more heat than it can handle. Hyperthermia can occur even on a mild day. Studies have shown that the temperature inside a parked vehicle can rapidly rise to a dangerous level for children, pets and even adults. Leaving the windows slightly open does not significantly decrease the heating rate. The effects can be more severe on children because their bodies warm at a faster rate than adults.
 Heat Safety

Child Safety Tips

  • Make sure your child's safety seat and safety belt buckles aren't too hot before securing your child in a safety restraint system, especially when your car has been parked in the heat.
  • Never leave your child unattended in a vehicle, even with the windows down.
  • Teach children not to play in, on, or around cars.
  • Always lock car doors and trunks--even at home--and keep keys out of children's reach.
  • Always make sure all children have left the car when you reach your destination. Don't leave sleeping infants in the car ever!

Adult Heat Wave Safety Tips

  • Slow down. Reduce, eliminate or reschedule strenuous activities until the coolest time of the day. Children, seniors and anyone with health problems should stay in the coolest available place, not necessarily indoors.
  • Dress for summer. Wear lightweight, light-colored clothing to reflect heat and sunlight.
  • Put less fuel on your inner fires. Foods, like meat and other proteins that increase metabolic heat production also increase water loss.
  • Drink plenty of water, non-alcoholic and decaffeinated fluids. Your body needs water to keep cool. Drink plenty of fluids even if you don't feel thirsty. Persons who have epilepsy or heart, kidney or liver disease, are on fluid restrictive diets or have a problem with fluid retention should consult a physician before increasing their consumption of fluids. Do not drink alcoholic beverages and limit caffeinated beverages.
  • During excessive heat periods, spend more time in air-conditioned places. Air conditioning in homes and other buildings markedly reduces danger from the heat. If you cannot afford an air conditioner, go to a library, store or other location with air conditioning for part of the day.
  • Don't get too much sun. Sunburn reduces your body's ability to dissipate heat.
  • Do not take salt tablets unless specified by a physician.
This page was produced as a cooperative effort of the National Weather Service, the Federal Emergency Management Agency and the American Red Cross. For additional information about Heat Waves and Heat Safety visit http://www.nws.noaa.gov/om/heat/.


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