Coping with heat injury and hypothermia in extreme environments and cardiac risks during exercise

Heatstroke is a life-threatening emergency. It occurs when the body's primary cooling mechanism-sweating-fails, causing the body temperature to exceed 110 degrees Fahrenheit. In this state, the brain is essentially "cooked." Blood flow decreases, and the kidneys shut down due to insufficient blood supply. Warning signs of heatstroke include confusion, chills, headache, dizziness, nausea, dry skin, euphoria, or a feeling of impending death. Heat exhaustion often precedes heatstroke, but is less severe and characterized by cold, clammy skin, sweating, weakness, dizziness, and nausea. Heat stress is a mild functional disorder caused by insufficient blood supply to the brain, which can lead to fainting, cramps, and prickly heat. Experienced runners are more prone to heat injury than beginners because they often engage in extreme training. Other individuals are also susceptible to heat injury, such as those who are thin, unaccustomed to hot weather activities, overweight, or too young or too old. Heart patients, kidney patients, diabetics, people with high blood pressure, and those with a history of heatstroke are more prone to heatstroke or heat exhaustion. People taking diuretics, sedatives, tranquilizers, or medications that affect the heart and blood pressure are at high risk of heatstroke due to altered sweating ability. Heatstroke and heat exhaustion are both emergencies. Patients should immediately stop physical activity, move to a shady place, pour cool water over them, rub ice on their skin, adopt a head-down position with feet elevated, and never force-feed water. Call emergency medical services immediately. Having an exercise partner is invaluable in such situations. Preventing heat injury: If you belong to a high-risk group, avoid overexertion; engage in adaptive exercise in hot weather for at least 15 minutes daily for 3 weeks; be cautious when the outdoor temperature and humidity index rises to 80°F; drink 1-2 cups of beverage every 20-30 minutes during prolonged strenuous exercise; avoid alcohol before and after exercise in hot weather to prevent dehydration; wear light-colored, lightweight, loose-fitting cotton clothing (including hats) to allow for air circulation and evaporation; avoid extra salt intake, as it increases thirst. Hypothermia is the opposite of heatstroke, referring to a body temperature dropping below 95°F. This condition can even occur when outdoor temperatures are above freezing. Symptoms include: violent shivering, dizziness, weakness, loss of control, confusion, hallucinations, slowed pulse, low blood pressure, and even cardiac arrest and death. Typical sufferers include: hikers, skiers, mountaineers, kayakers, swimmers, marathon runners (running in wet, cold weather), and cyclists (exposed to wind and rain). It is most likely to occur among unfit, underweight, poorly dressed, and inexperienced amateur athletes who underestimate the dangers of prolonged exposure to cold and wind. The degree of hypothermia is often unknown, and many people die from falls, slips, and other accidents before hypothermia develops. Rapid rewarming is the basic life-saving measure for hypothermia. Wrap the patient in a blanket or sleeping bag, or squeeze between two warm, naked people in a blanket or sleeping bag; hot drinks such as tea can help. Do not give alcohol, as alcohol can cause a large amount of cold blood to rush to the heart, making the condition worse. At home, hypothermia patients can be rewarmed by bathing or showering in water between 100 and 116°F. Raise their arms and legs above the water, allowing the torso to warm up first. Hot water bottles or hot water bags can also be used. Never try to revive a hypothermia patient by shaking their head. Move them gently and call a doctor as soon as possible. Even after they have clearly regained consciousness, hypothermia patients may still need several days to be out of danger. Frostbite, caused by the freezing of tissue fluid in the skin, threatens winter athletes such as skiers and can also occur in areas where temperatures are above freezing. A frostbitten nose appears pale, and frostbitten fingers or feet will feel numb. Sometimes the only signs of frostbite are slight bluish discoloration and numbness. However, the lungs do not suffer frostbite because the upper respiratory tract can warm the cold air to body temperature before it reaches the lower lungs. For example, people living in Alaska, if they are physically fit, can breathe air at -70°F without any problems. Canadian ski instructors advise people to observe their noses. When the nose initially turns pale, they suggest removing gloves and covering it with your palm for 1-2 minutes, without rubbing. When the limbs feel numb, especially when standing still or riding a cable car uphill, wiggle your toes and swing your arms. Runners and cyclists wearing shirts or T-shirts in cold weather are prone to hypothermia, frostbite, and penile frostbite. To prevent hypothermia and frostbite: wear multiple layers of clothing, including underwear, which can wipe away sweat and create an air insulation layer around the skin. Wear a breathable, waterproof raincoat on top; keep dry, don't wear too many layers, and avoid tight shoes and clothing to prevent sweating. Non-permeable clothing traps sweat, and wet clothing clinging to the body does not provide warmth. Maintain a balanced and regular diet, and avoid medication and alcohol. Alcohol does not "warm" you and instead dilates blood vessels, accelerating heat loss. Be careful of cold winds. Even winds of 20 mph can increase the risk of frostbite and hypothermia when outdoors at 15°F. Keep moving around to maintain blood circulation. But to survive in cold water, stay still to minimize heat loss and the cooling effect of the water flowing over your body. Avoid dehydration. You may not sweat in winter, but you will still lose fluids through respiration. Avoid fatigue. It makes you more susceptible to cold damage. Don't smoke. It constricts blood vessels, restricts blood supply to the limbs, and increases the risk of frostbite. Many people die in their sleep, while having sex, driving, or even defecating, but this is not uncommon for people to die from exercise. Many exercise-related deaths are caused by overexertion in people with pre-existing heart conditions. This includes congenital heart defects or those occurring in people over 40, coronary artery disease (caused by fatty deposits in the arteries supplying blood to the heart). Many people who die from exercise ignore warning signs of heart disease, such as chest discomfort or pain, pain in the jaw, arms, neck, throat, or shoulders; dizziness; fainting; moderate to severe fatigue; and/or extreme shortness of breath caused by exercise. Jim Fix, a 52-year-old long-distance runner and author who died of a heart attack, was a prime example of this negligence. In the months leading up to his fatal heart attack on July 20, 1984, he experienced chest and throat pain and tightness during exercise (symptoms of angina, a sign of coronary heart disease), but he ignored them. Fix's father had his first heart attack at age 35 and died of coronary heart disease at age 43. Fix also repeatedly refused to undergo treadmill stress tests; his autopsy revealed severe narrowing of three major coronary arteries supplying blood to the heart. A 14-month study of exercise-related deaths in the Seattle area showed that the risk of death from cardiac arrest during strenuous exercise is high, but regular exercise can significantly reduce the risk. For example, men who engage in at least 2 hours and 20 minutes of strenuous exercise per week have a five times higher risk of dying from heart disease during exercise compared to other times. However, people who almost never exercise have a 56 times higher risk of heart disease than those who engage in moderate exercise. Even just 20 minutes of regular exercise per week carries a lower risk of dying from heart disease at any time than sedentary individuals. In other words, regular exercise can generally reduce the risk of coronary heart disease, and its benefits far outweigh the temporary increase in the risk of sudden death during strenuous exercise. The basic argument is that the benefits of exercise outweigh the risks, and it has significant medical value for high-risk individuals. It is important to learn how to exercise safely and to pay attention to the symptoms of heart disease.