From the library of

Frank Barnhill M.D.
 

It is not true that heat stroke always causes brain damage!

You can suffer a heat stroke while sitting in a lawn chair relaxing in your back yard!

Dehydration and the body’s inability to get rid of excess heat are the principal causes of heat related illnesses. (See “Heat stroke and other heat related illnesses” at www.drhuggiebear.com).

You lose significant amounts of heat as sweat evaporates from your skin.

Many situations can make you prone to developing a heat related illness. Our goal in this article is to inform you of medications, illnesses, chronic conditions, and environments that can predispose you to heat related disorders. And before we close, we’ll review general signs and symptoms of dehydration and impending heat related conditions.

Here are the bear facts about causes for heat related illnesses: 

Medications
Blood pressure medications particularly diuretics or fluid pills (dehydration)
Drugs that constrict blood vessels such as anti-histamines and prostate medications (diverts blood flow from the skin)
Beta blockers cause the heart to beat slower (makes it difficult to adequately keep up with excess blood flow to the skin to get rid of heat)
Nerve pills that have effects similar to anti-histamines

Foods or ingestants that act like medications
Alcohol causes dehydration by increasing urine output
Caffeine constricts some blood vessels and leads to less sweating as a result
Street drugs such as amphetamines and cocaine decrease sweating
Any sedating food or drug can alter your thinking such that you fall asleep in direct sun or forget to use cool-down periods for rest
Over the counter herbal supplements that act like anti-histamines 

Medical illnesses and conditions
Diabetes when blood sugars are high and a state of relative dehydration exists, as blood gets “thicker”
Congestive heart failure patients often avoid drinking water so they don’t get swelling of their ankles or urinate a lot
Heart attack and heart bypass patients often can’t produce blood pressures adequate for the increased skin blood flow necessary for sweating due to direct heart damage or the medications to treat such conditions cause the heart to pump slower than normal
Chronic lung disease patients may already be breathing rapidly and really have little reserve to increasing respiration (respiration is one of the ways the body losses heat)
Any active infection (pneumonia) causes the need for the body to direct excess blood flow to the infected body part, reducing what’s available for sweating

Diseases that cause problems with heat, but not necessarily cause heat strokes
Uncontrolled thyroid disease can cause patients to be intolerant of heat
Connective tissue disorders such as Lupus and Multiple Sclerosis can act up as a result of too hot conditions
Asthma and allergies can flare when heat causes overgrowth of molds and excess pollen production
Heat edema is swelling of the arms or legs from excessive sun or heat exposure 

Situations that dispose to heat stroke
Working, living or just being in hot, humid environments with little or no air flow (in the back yard)
Living in a house with no air conditioning, fans, the windows shut, and no surrounding shade to cool the house during the hottest times of the day
Wearing constrictive tight clothing (nylon) that doesn’t allow for loss of sweat.
Applying excessive sweat blocking cream or cosmetics
(The worse heat stroke victim I ever saw was exercising in June in a sweat suit made of metallic cloth. It was airtight and it’s maker guaranteed weight loss by forcing sweat out of the body.)
Wearing long sleeve, long panted dark clothing
Trying to exercise in the heat for the first time or without exercise for a long time (couch potatoes and weekend warriors/athletes)

Symptoms of dehydration
Increase in thirst
Feeling tired or muscle fatigue
Dry mouth
Increased heart rate and rate of breathing
Irritability with feelings of uneasiness
Feeling hot despite removing or loosening clothing

Signs and symptoms of progressing heat related illness
(from mild to severe)
Profuse sweating
Hot, wet skin
Rapid heart rate
Increased respiration rate
Muscle cramps in arms, legs, abdomen
Muscle weakness
Dizziness
Mild Headache
Nausea
Fainting
Vomiting
Cold clammy skin with chills
Very rapid heart rate
Grossly excessive thirst
Agitation and confusion
Fever over 104 degrees Fahrenheit
Warm or hot dry skin as blood flow to the skin and sweating shut down
Very rapid heart rate and breathing
More severe headache
Uncontrollable twitching of muscles
Seizures
Loss of consciousness with coma
Death

Please remember: Anything that interferes with your body’s ability to regulate its temperature by sweat and perspiration predisposes you to heat effects and disorders.

These tips should help you enjoy warm and hot weather and protect you and your family from heat related illnesses!

Dr. Frank