Most
heat-related illnesses occur when victims have been overexposed to heat or have
over-exercised for their age and/or physical condition. When extreme heat is at
its most deadly, it kills by forcing the human body beyond its capacity to cool
itself down, slowing the processes by which normal body temperature is
maintained.
Who’s at risk?
Heat-related
illnesses and deaths are preventable. When extreme heat occurs, it’s important
to be aware of those at greatest risk for experiencing its effects: the very
young, the elderly, and people with chronic diseases and/or mental illness.
Even young and healthy individuals, however, can succumb to heat if they take
part in overly strenuous physical exercise outdoors during hot weather.
People
living in urban areas are at high risk also, thanks to the poor air quality of
many large cities and often-stagnant atmospheric conditions, which trap
pollutants in the air. When people breathe in these pollutants, they can
trigger a wide range of respiratory problems.
Asphalt
and concrete also store heat longer and gradually release heat at night,
leading to higher evening temperatures. Known as the urban “heat island”
effect, this can prevent or reduce nighttime relief from extreme heat in a
large city.
What are the effects?
In
regions where low humidity is the norm, the body’s most common response to
extreme heat is dehydration. When exposed to direct sunlight and temperatures
higher than 90 degrees Fahrenheit, the body can lose as much as half a gallon
of water every 10 minutes. This dehydration also can interfere with the body’s
internal thermostat, leaving it vulnerable to heat-related illnesses such as
severe sunburn, heat cramps, heat exhaustion and heat stroke.
In
regions of high humidity like the southeastern U.S., excessive heat can make
going outdoors nearly unbearable. High humidity also can interfere with the
body’s ability to sweat, which helps it cool down. When the heat outside
exceeds the level the body can remove through sweating and evaporation, body
temperatures rises and heat-related illness may develop.
Danger signs
No
matter where you live, it is important to recognize the real dangers of extreme
heat and take action to offset its impact at the earliest stages. The gradual
nature of extreme heat’s effects on the body makes it important to be aware of
these heat-related illnesses:
Severe sunburn
Marked
by skin redness and pain as well as swelling, blisters, fever and headaches.
More than simply a dermatological issue, severe sunburn reduces the body’s
ability to release excess heat and can leave you vulnerable to other
heat-related illness.
If
you or someone else experiences severe sunburn, take a shower with soap to
remove any oils that can block pores and prevent the body from cooling
naturally. If blisters are present, apply dry, sterile dressings and get
medical attention.
Heat cramps
Experienced
as painful muscle spasms, usually in the leg and/or abdomen. They are caused by
heavy exertion in the heat, which triggers heavy perspiration. Someone with
heat cramps should go immediately to a cooler location and lightly stretch and
massage the affected muscles to relieve the spasms.
Give
sips of up to half a glass of cool water every 15 minutes, and avoid drinks
with alcohol and caffeine. Discontinue liquids if the victim experiences
nausea.
Heat exhaustion
Heat
exhaustion is a mild form of shock, marked by heavy sweating; weakness; cold,
clammy skin; a weak pulse; fainting, and vomiting. This usually occurs when
people have been exercising heavily or working in a warm, humid place. Blood
flow to the skin increases in an attempt to cool the body, causing blood flow
to vital organs to decrease.
Victims
should be moved to a cooler location, and their clothing should be loosened or
removed if necessary. Apply cool, wet cloths and give sips of water if the
victim is conscious, taking care to ensure the water is consumed slowly. Give
half a glass of cool water every 15 minutes, and discontinue if the victim
experiences nausea and seek medical attention immediately if vomiting occurs.
If
left untreated, a victim’s condition can worsen. The body temperature can keep
rising, possibly leading to a heat stroke.
Heat stroke
Marked
by a very high body temperature (105 degrees or above) as well as hot, red, dry
skin; rapid, weak pulse; and rapid, shallow breathing. The victim will probably
not be sweating unless the sweating is due to recent strenuous activity. The
victim also may be unconscious.
Heat
stroke is a life-threatening condition in which the body’s internal thermostat
has ceased to function. The ability to sweat often stops, and the body’s
temperature can rise high enough that brain damage and death may occur in 10 to
15 minutes unless medical help is immediate. Call 911 immediately or get the
victim to a hospital as quickly as possible.
Until
medical attention arrives, try cooling the victim down with a cool bath and
cool, wet sponging, or a wet sheet to help lower body temperature. Watch for
breathing problems and use fans and air conditioners as well.
Source:
Centers for Disease Control and Prevention