Heat Safety and First Aid

EXTREME HEAT 

The human body dissipates heat by varying the rate and depth of blood circulation, by losing water through the skin and sweat glands, and (as the last extremity is reached) by panting when blood is heated above 98.6⁰F. The skin handles about 90% of the body's heat dissipating function.  However, sweating does not cool the body unless the water is evaporated.  Evaporation is a cooling process. 

On hot days (temperature above 90⁰F) when the relative humidity is high, evaporation is retarded.  The body attempts to do everything it can to maintain 98.6⁰F inside.  The heart is pumping a torrent of blood through dilated circulatory vessels-, the sweat glands are pouring liquid, including essential dissolved chemicals like sodium and chloride, onto the surface of the skin.

Heat disorders generally have to do with a reduction or collapse of the body's ability to shed heat by circulatory changes and sweating, or a chemical (salt) imbalance caused by too much sweating.  When heat gain exceeds the level the body can remove, or when the body cannot compensate for fluids and salt lost through perspiration, the temperature of the body's inner core begins to rise and heat-related illness may develop.

Other factors: Cities can add to the hazard.  Stagnant air conditions trap pollutants in urban areas and add the stresses of severe pollution to the already dangerous stresses of hot weather.  Sunburn can significantly retard the skin's ability to shed excess heat.  People on certain medication or drugs (such as tranquilizers and anticholinergics) and people overweight or with an alcohol problem are particularly susceptible.

What you should do to prevent heat disorders-.

A.   Slow down.  Reduce, reschedule, or eliminate strenuous activity.

B.   Dress for the summer.  Wear light-weight, light-colored clothing.

C.   Drink plenty of water.

D.   Do not get too much sun. 

The Heat Index combines the effects of high temperature and relative humidity.  Using the current temperature and relative humidity, calculate the heat index using the chart provided.  Exposure to full sun can increase these values by up to 15 degrees.  When the NWS is expecting the heat index to exceed 105⁰F, this will be headlined in the forecast.  At Heat Indices above 105⁰F, possible heat disorders include heat cramps or heat exhaustion.  Heat stroke is possible with prolonged exposure and/or physical activity.

First Aid

A.       Heat cramps are painful spasms usually in muscles of legs and abdomen.  Use firm pressure on cramping muscles, or gentle massage to relieve spasm.  Give sips of water unless nausea occurs.

B.       Heat exhaustion symptoms include heavy sweating, weakness, cold, pale clammy skin; and/or thready pulse.  Fainting or vomiting may occur.  Get the victim out of the sun, lay them down and loosen clothing.  Apply cool wet cloths.  Give sips of water unless nausea occurs.  If vomiting continues, seek immediate medical attention.

C.       Heat stroke (sunstroke) is when the body temperature reaches 106⁰F.  Symptoms are hot dry skin and rapid and strong pulse.  The person may become unconscious.  Heat stroke is a severe medical emergency; summon medical help immediately or take victim to a hospital.  While awaiting medical help, move the victim to a cooler environment.  Reduce the body temperature with a cool bath or sponging.  Use fans or air conditioners.  Do not give fluids.