What Is Heat Exhaustion? How to Prevent and Treat Heat Injuries
Personal, internal factors contribute to heat illness almost as much as external heat.
Heat illnesses may sound made up until you experience them for yourself. I assure you - they are very real, and once you've received a heat illness, you can increase your chances of additional heat injuries for the rest of your life.
I am Red Cross First Aid Certified and have heard variations on the same heat illness presentation time and again, but I'm 'young and stupid,' so it took two personal encounters with dehydration and heat exhaustion to make the message sink in. I hope you don't have my dedication to hands-on learning and can benefit from my mistakes. If you pay attention to the following information, instead of viewing it as another mandatory workplace training, you may be able to literally save a life.
A variety of external and internal factors affect your likelihood of developing a heat illness. Temperature, humidity, level of physical fitness, clothing color and material, medications, medical conditions, and even consuming caffeine or alcohol can influence your chances of developing a heat-related illness.
Heat illnesses cause more deaths each year than any other weather-related ailment. Children left in cars, athletes, people who work outdoors, the elderly, and anyone left without power during a heat wave are particularly susceptible, but a heat illness can strike anyone. The least severe heat illness are heat rash and heat cramps. These are uncomfortable and need treatment, but are not immediately life threatening. Once an individual develops heat exhaustion, he or she can quickly progress to the level of a heat stroke and can die. Even individuals who survive heat stroke can be left with lifelong consequences.
Prior heat illnesses can make you more susceptible to heat for the rest of your life. Protect your future by preventing heat illness today.
Risk Factors for Heat Illness
Heat is the common factor involved with all heat illnesses, but the thermometer reading only tells part of the story. The temperature, relative humidity, and dew point all affect your body's ability to cool down. For a detailed explanation of these factors and how they impact you, read my explanation of the heat index. However, a comfortable temperature for one person could cause heat stroke in another because a variety of other factors come into play.
Both the young and old are at increased risk for heat illnesses, and your sensitivity to heat increases with age. A temperature that suited you fine in your 20s may seem unbearably hot in your 40s. Generally, more physically fit, and leaner, people are less susceptible to heat illness. Your genetics also play a role - some people are simply more heat tolerant than others. No matter your genetic predisposition or physical fitness, sudden exposure to heat is hard on your body. It takes most people 2-5 days to adjust to heat, so suddenly arriving at a new, hotter location or the onset of a heat wave can cause problems, even if the same temperatures were bearable to you at other times.
Additionally, many different types of medication impact your body's ability to stay hydrated. Most vasoconstrictors, medications that narrow your blood vessels, and blood pressure regulators increase your susceptibility to dehydration and heat illness. Any diuretic, or substance that causes you to produce urine, can lead to dehydration. Both caffeine and alcohol are diuretics, so make sure to bring something other than beer and soda to the beach or on a boat ride. Stimulants, both legal and illegal, also increase your risk for dehydration.
I've heard people suggest wearing dark clothing on a hot day so damp sweat spots are less visible. This is a very harmful idea. If you need to be outdoors in the heat, wear light colors and loose, breathable clothing. Dark colors heat up in sunlight, causing you to sweat more and increasing your risk for dehydration. Tight clothing and non-breathable materials reduce your body's ability to shed heat.
Prior bouts of heat illness can also make a person more susceptible to future heat exhaustion and heat stroke. Some people who experience heat stroke have sensitivity to light, smells, and sounds for days, or even years, after the event.
Learn how Heat Affects Your Body
- What Is the Heat Index?
Learn about the heat index and how it affects your body's ability to cool down.
What Causes Heat Illnesses?
The human body tries to maintain a consistent core temperature. On average, this temperature is 98.6 degrees Fahrenheit or 37 degrees Celsius. When your body temperature gets too far above or below your personal healthy body temperature, stabilizing mechanisms kick in. When you're cold, you shiver, and when you're hot, you sweat. Heat illness occurs when your core temperature rises and normal body cooling mechanisms fail to bring it back to its normal, healthy range. Basically, having a heat illness is like maintaining a high fever while suffering from dehydration, which can be a fatal combination.
Need to Cool Down?
Heat Rash and Heat Cramps
Heat rash and cramps are the least severe heat illnesses. Heat rash is most common in young children and is simply a red, pimple-like rash. It is uncomfortable, but not immediately life-threatening and is easily treatable by moving to a cooler, dryer environment.
Heat cramps are muscle cramps or spasms, frequently in the abdomen, arms, and legs, that usually occur after physical exertion in hot weather. When you sweat excessively, your body looses moisture and salt. We spend so much time today worrying about getting too much salt and sometimes forget that our bodies need some salt. Low salt levels muscles is what causes painful heat cramping. Heat cramps can be a sign of heat exhaustion. If you have heat cramps, stop physical activity, get to a cooler place, and drink water, a sport drink, or juice to rehydrate. If the cramps have not subsided in an hour, seek medical attention.
Do not ignore heat exhaustion symptoms. Heat exhaustion can progress to deadly heat stroke in mere minutes.
Have you Suffered a Heat Illness?
I've experienced two bouts of heat exhaustion, so far. When I was in college, a water main broke and the city advised that you not drink the water until the problem was fixed. Anyone other than a college sophomore might have responded by buying a bottle of water or juice. Instead, I spent my entire Saturday running around outside playing sports with friends on a nice South Carolina April day. My afternoon concluded with me vomiting from dehydration, which I hadn't previously realized was possible. The second time I suffered heat exhaustion was recently. I was working outside when all of a sudden I felt queasy and shaky - my legs and arms literally felt to weak to support me. Even after rehydrating and cooling down, I felt 'off' for the next 24 hours.
Weakness, dizziness, headache, nausea/vomiting, muscle cramps, heavy sweating, and a suddenly pale appearance are all signs of heat exhaustion. Heat exhaustion is frequently caused by inadequate, or inappropriate, fluid replacement and can build over several days. The days preceding my more recent bout of heat exhaustion were far warmer than the day, itself, but I'd evidently gradually dehydrated myself.
You may notice signs of heat exhaustion in others before they are willing to admit to them. The same is true in reverse - if someone tells you that you look unusual and overheated, don't ignore them. Move immediately to a cooler environment, even if this is only shade, and loosen or remove clothing. Then, make sure the affected individual drinks water. Do not gulp water or drink overly cold water as this can stress your already overloaded system and cause you to vomit. Vomiting then leads to further dehydration and increases the risk of developing heat stroke. Draping a wet cloth around your neck or across your forehead can help you cool down. Sponge baths and showers are also effective at reducing body temperature.
Heat exhaustion can quickly progress to heat stroke, so you should take steps to cool down as soon as possible if you overheat. If you feel weak or dizzy, you may require assistance - do not be too proud to ask. By the same token, friends and family with heat exhaustion may be reluctant to ask for help. Do not let this person's stubbornness win - insist on providing appropriate, immediate care. Heat exhaustion is not something to shrug off - untreated, it can turn deadly.
Instant ice packs can be a literal lifesaver for someone experiencing heat stroke
Heat stroke is named for the stroke-like symptoms it produces. Confusion, difficulty speaking, and lack of coordination are hallmarks of a heat stroke. As with heat exhaustion, you are much more likely to notice these symptoms in others than yourself. A sudden cessation of sweating is also a key symptom of heat stroke. A throbbing headache, a body temperature of over 103 degrees Fahrenheit, a loss of consciousness, and seizures may also indicate heat stroke.
If you see someone exhibiting these signs, immediately call for emergency medical assistance and move the victim to a cooler location. Take any means possible to get his or her body temperature below 101 degrees. You can loosen or remove clothing, spray his/her body with water and fan vigorously, or even put them in an ice bath. Once again, give fluids, but do not allow the victim to drink anything with caffeine or alcohol as both can cause further dehydration. If a person is suffering from extreme dehydration, consider avoiding sports drinks. I know from personal experience that the sugars can be too much to handle and can actually lead to vomiting. When your body is so dehydrated you cannot sweat any more, your body may automatically reject anything that would require digestive processes.
Heat stroke is a serious medical emergency that requires immediate treatment. Failure to rapidly and appropriately treat heat stroke can lead to death.
FAQ's About Heat Illness
Q: Should I take salt tablets to replenish my body's salt supply after sweating?
A: No. Decades ago, 'conventional wisdom' said you should replace lost salts and minerals with salt tablets. Today, physicians do not recommend taking salt tablets. Most people receive the necessary salts and minerals in their regular diet. Those who work outside or exercise a lot can add sports drinks, but these are not actually necessary for most people.
Q: What if I have to go outside or work outside during hot weather?
A: Make sure to pre-hydrate by drinking at least a glass of water an hour before going outdoors. Half an hour before going outside, apply sunscreen. Sunburned skin cannot shed heat effectively and increases your risk of heat illness. Also, make sure to pace yourself. Take breaks, if you need to, and start working slowly. Basically, you need to 'warm up' by gradually increasing the intensity of your work. If your heart is pounding and sweat is dripping off your face, get to a shady area and rehydrate before resuming work.
Q: How much water should I drink during hot weather?
A: The amount of water you need depends on many personal and environmental factors. However, you should try to drink between 16 and 32 ounces (2-4 cups) of cool liquid for each hour of heat exposure. Water, juices, and sports drinks are all hydrating and appropriate, but you should avoid dehydrating alcoholic and caffeinated beverages.
Prevent Heat Illness
Hundreds of people die each year from heat illnesses, even though they are preventable. By learning the symptoms of and treatments for heat illnesses, you can protect yourself and those you care about. If you are planning a day of fun in the sun, make sure everyone in your group reads up on heat illnesses and set up a buddy system. Forgetting to hydrate is easy and it can be difficult to notice your own symptoms of heat stroke. By setting up a buddy system, you and your partner can monitor each other for heat illness symptoms and make hydration reminders.
Don't wait until you suffer a heat illness - educate and protect yourself today.