Heat Stroke and Other Heat Related Illnesses   Frank Barnhill M.D.

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Itís a myth that heat stroke only occurs when a person gets too hot or is in an extremely hot environment!

 It is true that any longstanding disease such as diabetes, heart, and lung disease can lower your ďresistanceĒ to heat related illnesses.

 It is likewise true that heat strokes tend to occur more in the very young and the much older person.

Everyone has heard about someone else having a heat stroke at one time or another. More often than not, the person who suffered the heat related insult survived and fully recovered. Most people donít realize a good percentage of true heat stroke victims die (400 to 500 per year) or have continuing medical problems after their near disaster. So, the vast majority of those who suffer a heat disorder obviously donít have heat strokes.

Heat stroke is just one of four heat related illnesses caused by failure of our bodies to get rid of heat faster than we make it or absorb it. The human body normally effectively gets rid of excess heat by shunting extra blood flow to our skin so that sweating and evaporation (convection) and to a lesser extent, rapid breathing, will carry that heat off in the surrounding air. Sweating is the bodyís most efficient way to decrease and control central body temperature. When we take a quick dip in the pool to get cooled off after working in the yard, heat is directly transferred to water (conduction), bypassing the evaporation process. So, obviously, a rapid way to lower body temperature is by wetting a person with cool (not cold) water.

Letís now take a look at the different types of heat related illnesses and situations or conditions that can make it more likely you could fall victim to one of the four disorders.

Heat cramps are the mildest of the four disorders and result from mild dehydration and loss of body sodium. These very painful muscle spasms usually occur in the arms, legs, or lower abdomen. Youíve seen heat cramps strike athletes as they over-exert themselves in a very warm environment. Older persons on diuretics or fluid pills are particularly prone to this condition.

Replacing lots of water and using sodium containing drinks and letting the affected person rest in cooler surroundings will usually lead to a rapid recovery. You can help your children avoid getting heat cramps by letting them drink high sodium (salt) containing sports drinks before playing in hot conditions.

Heat syncope (passing out, loss of consciousness or feelings of faintness with dizziness) is the second most serious heat related illness and occurs as heat cramps go undetected or ignored and untreated. In really hot situations or with very strenuous exercise or work, the affected person may actually progress from muscle cramps to syncope before they are able to seek treatment.

The dizziness and fainting of heat syncope occurs because dehydration makes it difficult for your body to maintain normal blood pressures, blood flow to your brain and provide excess skin blood flow to lower your core body temperature at the same time!

Heat syncope patients typically complain of profound weakness, of being very tired and then become dizzy or faint after heat exposure. This often occurs in persons standing for a long time, become dehydrated and proceed to exercise in hot conditions, or jump up from a sitting position and try to restart exercise without adequate cool-down or slow warm-up (acclimation) periods.

This condition is best treated by letting the person lie down, not sit, and giving cool oral re-hydration in a cool environment. However, if this person is still unconscious or canít take fluids by mouth, you should seek medical attention immediately!

Heat exhaustion occurs when your body loses large amounts of water and salt through perspiration and is the third most serious of the heat-associated disorders. Heat exhaustion commonly occurs with strenuous exercise or very strenuous physical labor, but can occur in inactive persons on low salt diets and diuretics in hot environments.

Heat exhaustion is associated with all of the above-mentioned symptoms plus profuse hot sweating, headache, blurry vision, loss of appetite, nausea, vomiting, chills, muscle weakness, skin flushing, extreme thirst, irritability, agitation, and sometimes loss of consciousness and rarely seizures.

Even though your skin would be hot and sweaty because your body is desperately trying to get rid of heat, core body temperatures in heat prostration rarely go above 103 to 104 degrees Fahrenheit.

Though rarely life threatening, heat exhaustion requires immediate first aid type attention as it may progress to heat stroke. The very same treatment used in heat syncope will often work, but if the affected person becomes confused, passes out, has difficulty breathing, starts vomiting, or has a seizure, you must seek emergency medical attention immediately! It may help to remove about half of the personís clothing to assist in evaporation of sweat.

Heat stroke is of course the worse of the heat related illnesses and is a true life-threatening medical emergency.

Persons suffering from heat stroke have very high body temperatures, often in the 104 to 109 degree range, but when touched, will have a hot, dry skin. This paradox occurs as your bodyís blood pressure starts to drop as a result of dehydration and must shunt blood back to the brain and vital organs to preserve life.

Other symptoms include all of those encountered with heat exhaustion to more extremes and sudden shortness of breath, seizures, decreased urination and sometimes blood in the urine, unconsciousness followed by coma, and if untreated, death. You must call 911 immediately to save this personís life.

While waiting for an ambulance, remove all clothing, spray the person with cool water, place ice packs on the neck, wrists, ankles and groin, armpits, and if conscious and not vomiting or delirious, give cool liquids to drink.

The sickest heat stroke victim I ever treated was simply cutting the grass on a 90 degree August day after drinking a quart of water and taking a salt tablet. His symptoms occurred so rapidly, his wife found in lying in the yard ten minutes after he came in to drink the water and cool off for ten minutes.

On arrival in our emergency room, he was unconscious, had vomited, with a rectal temperature of 112 degrees Fahrenheit, breathing 45 times a minute, with no blood pressure and a very faint pulse.

We started cold intravenous fluids, inserted a submergible rectal thermometer and placed him in a whirlpool filled with ice water. He had a seizure almost immediately, required IV Dilantin, but dropped his core body temperature to 109 in less than seven minutes. Within thirty minutes, we had a stable temperature of 101 and could remove him from the ice bath. He was very lucky and survived with no permanent brain, heart, or kidney damage.

The above-described treatment should only be attempted by medical personnel experienced in handling the complications of such therapy. As body temperatures drop, itís not uncommon for the afflicted person to suffer seizures, stop breathing or have cardiac arrest!

This patient had high blood pressure, was taking a strong diuretic, was on a very low salt diet, and was a couch potato. All of these conditions can predispose you to heat related illnesses.

So, what can you do to keep from developing heat related illnesses?
Drink lots of water on hot days.
Listen to the weatherman and avoid being outside or in direct sun at the hottest times of the day.
If you donít have air conditioning, use fans to cool and move air to help with perspiration evaporation or go to an air-conditioned store or mall during the hottest parts of the day.
Avoid caffeine and alcohol. Both alter the way your body provides blood flow to the skin allowing sweating and evaporation of heat.
Wear light colored, lightweight clothing such as cotton when exposed to excessively hot temperatures or when you plan to be outdoors for more than 30 minutes.
Talk to your doctor about your medications and what you should do about water, salt containing sports drinks and exercise or exertion in heat.
When standing in hot conditions for long periods, such as watching sports events or a parade, avoid sudden exertion, drink water as you watch, wear a hat and if you get too hot, spray your skin with water, loosen clothing or go inside to cooler temperatures.
Wet clothing does not provide as much heat loss as wet skin from which water may evaporate!
Know your work-play heat related limits. Plan for rest and cool off times when working in the yard or during exercise and recreation.
Go slowly at whatever you plan to do in hot environments. Acclimation occurs as a person slowly gets used to being in the heat.
Hopefully these tips and items of knowledge will help you protect yourself and family from the disasters known as heat related illnesses.

Dr. Frank

These health tips are offered for your common sense use and are not intended to take the place of a visit to your doctor.  Your use of the materials implies your understanding that nothing herein contained represents individual medical advice.

drhuggiebear, drhuggiebear.com and contained materials are the copyrighted and/or registered properties of Frank Barnhill, M.D. and may not be reproduced for profit without the express written permission of the author.  All materials may be photocopied in whole for educational use.  For information please contact us at drfrank@drhuggiebear.com.

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