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Skip Navigation LinksPennsylvania Department of Health > My Health > Environmental Health > Health Tracking Program > Heat-related conditions

heat-related conditions

Heat Illness or Heat-related Illness is a Spectrum of Disorders
Due to Environmental Heat Exposure

HEAT STRESS
Heat stress is when the body is unable to cool itself by sweating.  When the air temperature is close to or warmer than normal body temperature, cooling of the body becomes more difficult.  Blood circulated to the skin cannot lose its heat.  Sweating then becomes the main way the body cools off.  However, sweating is only effective if the humidity level is low enough to allow evaporation, and if the fluids and salts that are lost are adequately replaced. If the body cannot get rid of excess heat, it will store it.  When this happens, the body’s core temperature rises and the heart rate increases.  As the body continues to store heat, other heat related illnesses start to occur. 
 
HEAT STROKE
Heat stroke is the most serious heat-related disorder. It occurs when the body becomes unable to
control its temperature. The body’s temperature rises rapidly, the sweating mechanism fails, and the
body is unable to cool down.  When heat stroke occurs, the body temperature can rise to 106 degrees
Fahrenheit or higher within 10 to 15 minutes.  Heat stroke can cause death or permanent disability if
emergency treatment is not given.
Symptoms of heat stoke include the following:
      -  Hot, dry skin or profuse sweating
      -  Hallucinations
      -  Chills
      -  Throbbing headaches
      -  High body temperature
      -  Confusion\dizziness
      -  Slurred speech
Heat stroke follows two less serious heat-related conditions: heat cramps and heat exhaustion.
 
HEAT CRAMPS
Heat cramps usually affect people who sweat a lot during strenuous activity. This sweating depletes
the body’s salt and moisture levels.  Low salt levels in muscles causes painful cramps.  Heat cramps
can also be a symptom of heat exhaustion.  Symptoms of heat cramps include muscle pain or spasms usually in the abdomen, arms or legs.
 
HEAT EXHAUSTION
If heat cramps is not treated properly, the condition will worsen into heat exhaustion. Heat
exhaustion is the body’s response to an excessive loss of the water and salt, usually through
excessive sweating.  People that are most prone to heat exhaustion are the elderly, those with
high blood pressure and those working in a hot environment.
If heat cramps is not treated properly, the condition will worsen into heat exhaustion.Heat exhaustion is the body’s response to an excessive loss of the water and salt, usually through excessive sweating.  People that are most prone to heat exhaustion are the elderly, those with high blood pressure and those working in a hot environment. Symptoms of heat exhaustion include:
      -  Heavy sweating
      -  Extreme weakness or fatigue
      -  Dizziness, confusion
      -  Nausea
      -  Clammy, moist skin
      -  Pale or flushed complexion
      -  Muscle cramps
      -  Slightly elevated body temperature
      -  Fast and shallow breathing
 
HEAT SYNCOPE
Heat syncope is a fainting (syncope) episode or dizziness that usually occurs with prolonged standing
or sudden rising from a sitting or lying position.  It is a type of heat illness. Factors that may contribute
to heat syncope include dehydration and lack of acclimatization. Symptoms include:
      -  Light-headedness
      -  Dizziness
      -  Fainting
 
HEAT RASH
Heat rash is a skin irritation caused by excessive sweating during hot, humid weather. Symptoms
of heat rash include
      -  Red cluster of pimples or small blisters
      -  More likely to occur on the neck and upper chest, in the groin, under the breasts
         and in elbow creases.

RISK FACTORS FOR HEAT STRESS
 There are several risk factors for heat stress which include:
      -  High temperature and humidity
      -  Direct sun exposure
      -  No breeze or wind
      -  Low liquid intake
      -  Heavy physical labor
      -  Waterproof clothing

Prevention of Heat Illness and Heat-Related Conditions 
      -  Using air conditioning and ventilation if you are indoors 
      -  Drinking plenty of water and staying hydrated
      -  Avoid beverages containing alcohol or caffeine
      -  Block out direct sunlight or other heat sources
      -  Wear lightweight, light colored, loose fitting clothes
      -  When working in extreme heat and humidity take frequent breaks

PA EPHT and CDC’s role in tracking Heat-Related Conditions
PA EPHT and CDC track the effects of heat illness by collecting and reviewing the number of health
conditions reported from local hospitals and the number of deaths reported that are heat related. 
Reviewing this data helps scientist make comparisons between environmental conditions and health
problems. Other examples of how heat-related conditions data can be used is to identify populations
and areas with high risk for heat-associated deaths,  gain a better understanding of trends in heat-
related deaths over time, compare counties to plan interventions and to identify communities at risk
and groups of people that may be at risk. 
 
Not all groups of people are at equal health risk from heat.  Knowing where at-risk people are located can help counties and cities focus their resources most effectively to coordinate heat emergency plans