Bob liked to play basketball on the court at the local  park. It wasn't unusual for him to play his mid-afternoon  game no matter what the weather. Then, one hot and humid day, it caught up with him and Bob nearly died...from heat stroke.

                          "We get rid of heat mostly through evaporation which is helped along by sweating," says Richard Sandor, M.D., an orthopedist with the Camino Medical Group in California. "When it gets humid, or the person becomes dehydrated, the process is slowed and works less efficiently. The heat builds up faster than it can be reduced, and heat illness occurs."

                        Heat stroke is the most dangerous of the heat-related illnesses because it can be fatal. Statistics on how many athletes die or are injured due to overheating are not available. What is known is that, overall, heat stroke survival rates run between 90% and 100%, up from 20% earlier in the century.

                          "When the body heat begins to go up, it first impacts on two very important systems," says William Roberts, M.D., a family practice and sports medicine physician with MinnHealth Family Physicians. "The brain and the heart do not tolerate changes in temperature well, and begin to have problems."

                   Types of heat stroke

                          Heat stroke occurs in two forms, exertional and classic:
 

• Classic heat stroke (CHS) is talked about on TV during heat waves. It is recognized by changes in mental ability, high body temperatures and lack of sweating, the last being the most important. It is basically the environmental heat overwhelming the body's ability to cope with it.

• Exertional heat stroke (EHS) is of most concern to athletes. When we exercise, the use of muscles builds up heat internally. The humidity of the outside air makes getting rid of the extra heat harder. When temperature adds a heat load of its own, the likelihood of heat illness increases.

                          "In classic heat stroke, the build up of the body's temperature takes longer and it cooks you slowly," said Dr. Roberts. "In EHS  the temperatures build up much more rapidly and it cooks you by raising the core temperature faster."

                    The signs of exertional heatstroke

                         Bob had been playing basketball for a couple of hours now in the mid-afternoon sun. His play began to get ragged. Normally a skilled player, he started to run into people from both teams. He went left when he should have gone right. He was getting near collapse.

                          "In classic heat stroke, one of the major indicators that you are running into trouble is when you stop sweating," notes Dr. Sandor. "With exertional heat stroke, the victims often continue to sweat and the cardinal symptom is a change in mental status," he explains. "In many cases, because of the impact of heat on the brain, the person will not even realize they are in trouble, and continue to play."

                          With EHS, those competing against the victim may see the first symptoms:

                             ·         Conversations begin to make less sense.
                             ·         He is not able to tell the day or date.
                             ·         There are changes in his ability to perform.
                             ·         He begins to stumble and appear uncoordinated.
                             ·         His speech becomes slurred.

                          Other early indications include weakness and dizziness, which are also often ignored. The person may have a high pulse and may collapse. In some cases, he may develop chills or goose bumps. The best way to diagnose heat stroke, the rectal temperature, is usually not feasible. Other methods of taking a temperature such as under the tongue, the arm pit or in the ear don't show core body temperature and are not as useful in this situation.

                   What to do when someone has heatstroke

                          It was about four in the afternoon and they had been playing for a couple hours without a break. The court was in the middle of the  park without a shady spot in sight. Then, Bob collapsed.

                          Heat stroke is a medical emergency and requires an immediate call for an ambulance.

                          "Just because it is hot and humid and someone has collapsed, you cannot assume that it is heat stroke causing the problems,"stresses Dr. Sandor. "Make sure the person is breathing and has a pulse before doing anything else. If not, then begin CPR."

                          After having established that the victim is not in arrest, cooling him takes highest priority until an ambulance arrives. Both doctors recommend getting the person out of direct sunlight and into shade. Lay the person on his back with legs elevated to help increase blood flow to the brain.

                          "Place ice bags around [his] neck, in the armpits, and the groin area," says Dr. Roberts. "If these are not available, then a watering hose, cold wet towels or even cold pop cans could be used instead. The best thing would be an ice bath. Any tub or wading pool will do to immerse the trunk and legs while waiting for help to arrive."

                          Sweating causes the body to lose fluids making self-cooling more difficult. If the victim is still conscious and able to swallow, give him cold beverages to begin the rehydration process. Both physicians warn against using alcoholic drinks or those containing caffeine in people with heat illness. These are diuretics and cause the kidneys to actually filter more water out of the body and into the urine.

                    Keeping the heat from getting to you

                         Bob was among the 90% of those who recover completely from heat stroke. However, having been through the ordeal once, vowed he never wanted to do it again. Prevention became his quest.

                          "The best way to avoid heat-related illnesses is to always keep in mind the wisdom of Clint Eastwood: 'A man's got to know his limitations'," says Dr. Sandor. "Of heatstroke factors that are in the athlete's control, by far the three most important are lack of acclimatization, playing over one's head and dehydration. Though not in control of the weather, he or she should think about the conditions when deciding how long and how hard, or even if, [he or she] should play."

                                 Get used to the environment

                                Acclimatization means getting used to the environment. If you usually live in an area that has little or no humidity, prepare for a tournament in a hot, muggy town by getting there two or three days early. Do some light running or exercising to get your body used to the changes. Moderately increasing your salt intake for a few days is also recommended.

                                Drink plenty of fluid

                                Keeping a steady intake of fluids is an easy way to avoid most heat stroke. An active person normally sweats off about one to two liters per hour. Dr. Roberts suggests drinking about eight ounces or so of water or a sports drink roughly every 15 minutes. For periods of less than an hour, water is all that is needed. If the activity is longer, sports drinks replace much of the salt and other minerals lost through sweating.

                                Use your head

                                "The key to avoiding heat injuries is really just common sense," says Dr. Roberts. "If there is too much heat and humidity, just don't play. If  you do, stop play and cool off at intervals by  getting into a shaded area or an air conditioned
building or car." Keep out of the sun between noon and 2:00 p.m. And wear a hat.

This article originally appeared in Healthy Athlete @ www.bewell.com, Sept. 1999.
 

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