HEAT STROKE - SUN STROKE
What can you do in case you have it?
What is a heat stroke?
Heat stroke is a condition caused by your body overheating, usually as a result of prolonged exposure to or physical exertion in high temperatures. This most serious form of heat injury, heatstroke, can occur if your body temperature rises to 104 F (40 C) or higher. The condition is most common in the summer months.
Heat stroke requires emergency treatment. Untreated heat stroke can quickly damage your brain, heart, kidneys and muscles. The damage worsens the longer treatment is delayed, increasing your risk of serious complications or death.
Who is at risk of a heat stroke?
Heat stroke is not the same as a stroke. "Stroke" is the general term used to describe decreased oxygen flow to an area of the brain.
Those most susceptible (at risk) individuals to heat stroke include:
- The elderly (often with associated heart diseases, lung diseases, kidney diseases, or who are taking medications that make them vulnerable to dehydration and heat strokes)
- Individuals who work outside and physically exert themselves under the sun
- Infants, children, or pets left in cars.
Heat stroke is sometimes classified as exertional heat stroke (EHS, which is due to overexertion in hot weather) or non-exertional heat stroke (NEHS, which occurs in climatic extremes and affects the elderly, infants, and chronically ill.
Heat stroke is most likely to affect older people who live in apartments or homes lacking air conditioning or good airflow. Other high-risk groups include people of any age who don't drink enough water, have chronic diseases, or who drink excessive amounts of alcohol.
Heat stroke is strongly related to the heat index, which is a measurement of how hot you feel when the effects of relative humidity and air temperature are combined. A relative humidity of 60% or more hampers sweat evaporation, which hinders your body's ability to cool itself.
The risk of heat-related illness dramatically increases when the heat index climbs to 90 degrees or more. So it's important especially during heat waves to pay attention to the reported heat index, and also to remember that exposure to full sunshine can increase the reported heat index by 15 degrees.
If you live in an urban area, you may be especially prone to develop heat stroke during a prolonged heat wave, particularly if there are stagnant atmospheric conditions and poor air quality. In what is known as the "heat island effect," asphalt and concrete store heat during the day and only gradually release it at night, resulting in higher nighttime temperatures.
Other risk factors associated with heat-related illness include:
Age. Infants and children up to age 4, and adults over age 65, are particularly vulnerable because they adjust to heat more slowly than other people.
Health conditions. These include heart, lung, or kidney disease, obesity or underweight, high blood pressure, diabetes, mental illness, sickle cell trait, alcoholism, sunburn, and any conditions that cause fever.
Medications. These include antihistamines, diet pills, diuretics, sedatives, tranquilizers, stimulants, seizure medications (anticonvulsants), heart and blood pressure medications such as beta-blockers and vasoconstrictors, and medications for psychiatric illnesses such as antidepressants and antipsychotics. Illegal drugs such as cocaine and methamphetamine also are associated with increased risk of heat stroke.
People with diabetes who are at increased risk of emergency room visits, hospitalization, and death from heat-related illness may be especially likely to underestimate their risk during heat waves, according to a recent study presented at the Endocrine Society's annual meeting by researchers from the Mayo Clinic in Arizona, the National Ocean and Atmospheric Administration, and the National Weather Service.
Check with your doctor to see if your health conditions and medications are likely to affect your ability to cope with extreme heat and humidity.
What are the symptoms of a heat stroke?
Heatstroke signs and symptoms include:
- High body temperature. A core body temperature of 104 F (40 C) or higher, obtained with a rectal thermometer, is the main sign of heatstroke.
- Altered mental state or behavior. Confusion, agitation, slurred speech, irritability, delirium, seizures and coma can all result from heatstroke.
- Alteration in sweating. In heat stroke brought on by hot weather, your skin will feel hot and dry to the touch. However, in heat stroke brought on by strenuous exercise, your skin may feel dry or slightly moist.
- Nausea and vomiting. You may feel sick to your stomach or vomit.
- Flushed skin. Your skin may turn red as your body temperature increases.
- Rapid breathing. Your breathing may become rapid and shallow.
- Racing heart Your pulse may significantly increase because heat stress places a tremendous burden on your heart to help cool your body.
- Headache. Your head may throb.
- Dizziness and light-headedness
- Lack of sweating despite the heat
- Muscle weakness or cramps
- Behavioral changes such as disorientation, or staggering
How to help a person who has a heat stroke?
If you suspect that someone has a heat stroke, immediately call 911 or transport the person to a hospital. Any delay seeking medical help can be fatal.
While waiting for the paramedics to arrive, initiate first aid. Move the person to an air-conditioned environment -- or at least a cool, shady area -- and remove any unnecessary clothing.
If possible, take the person's core body temperature and initiate first aid to cool it to 101 to 102 degrees Fahrenheit. (If no thermometers are available, don't hesitate to initiate first aid.)
Try these cooling strategies:
- Fan air over the patient while wetting their skin with water from a sponge or garden hose.
- Apply ice packs to the patient's armpits, groin, neck, and back. Because these areas are rich with blood vessels close to the skin, cooling them may reduce body temperature.
- Immerse the patient in a shower or tub of cool water.
- If the person is young and healthy and suffered heat stroke while exercising vigorously -- what’s known as exertional heat stroke -- you can use an ice bath to help cool the body.
Do not use ice for older patients, young children, patients with chronic illness, or anyone whose heat stroke occurred without vigorous exercise. Doing so can be dangerous.
If an emergency response is delayed, call the hospital emergency room for additional instructions.
- A blood test may be used to check your sodium or potassium levels to help determine if you are dehydrated.
- A sample of your urine may be taken. Dark yellow urine may be a sign of dehydration.
- Muscle function tests may be performed.
- Your doctor runs tests to check your kidney function.
- X-rays and other imaging tests can be used to determine if you have any internal organ damage.
If you begin experiencing symptoms of heat exhaustion, try to find a cooler location if possible. For example, if you are outside, look for a shady area. If you are indoors, remove a layer of clothing or turn on the air conditioning.
You may also want to lie down, or if that isn’t possible, stop doing any strenuous activities. That may help your body regulate temperature.
Drink water or a sports drink to help rehydrate yourself. Sports drinks have electrolytes, which your body loses through excessive sweating.
If you have become nauseated or vomit, seek help from a medical doctor right away.
A heat stroke is considered a medical emergency. Call your local emergency services immediately if you suspect that you’re having a heat stroke.
Your doctor may place you in a bath of cold ice water to lower your temperature quickly. They may also mist your skin with water, pack you in ice packs, or wrap you in a special cooling blanket. If the coldness causes you to shiver, your doctor may give you medications to stop the shivering. This might increase your body temperature.
ComplicationsHeatstroke can result in a number of complications, depending on how long the body temperature is high. Severe complications include:
- Vital organ damage. Without a quick response to lower body temperature, heatstroke can cause your brain or other vital organs to swell, possibly resulting in permanent damage.
- Death. Without prompt and adequate treatment, heatstroke can be fatal.
PreventionOne of the main ways to prevent heat-related illness is to keep your body temperature cooler. This is particularly important when you are working or doing activities outside in the heat or sun.
Heatstroke is predictable and preventable. Take these steps to prevent heat stroke during hot weather:
- Wear loose fitting, lightweight clothing. Wearing excess clothing or clothing that fits tightly won't allow your body to cool properly.
- Protect against sunburn. Sunburn affects your body's ability to cool itself, so protect yourself outdoors with a wide-brimmed hat and sunglasses and use a broad-spectrum sunscreen with an SPF of at least 15. Apply sunscreen generously, and reapply every two hours — or more often if you're swimming or sweating.
- Drink plenty of fluids. Staying hydrated will help your body sweat and maintain a normal body temperature.
- Take extra precautions with certain medications. Be on the lookout for heat-related problems if you take medications that can affect your body's ability to stay hydrated and dissipate heat.
Never leave anyone in a parked car. This is a common cause of heat-related deaths in children. When parked in the sun, the temperature in your car can rise 20 degrees F (more than 11 C) in 10 minutes.
It's not safe to leave a person in a parked car in warm or hot weather, even if the windows are cracked or the car is in shade. When your car is parked, keep it locked to prevent a child from getting inside.
- Take it easy during the hottest parts of the day. If you can't avoid strenuous activity in hot weather, drink fluids and rest frequently in a cool spot. Try to schedule exercise or physical labor for cooler parts of the day, such as early morning or evening.
- Get acclimated. Limit time spent working or exercising in heat until you're conditioned to it. People who are not used to hot weather are especially susceptible to heat-related illness. It can take several weeks for your body to adjust to hot weather.
- Be cautious if you're at increased risk. If you take medications or have a condition that increases your risk of heat-related problems, avoid the heat and act quickly if you notice symptoms of overheating. If you participate in a strenuous sporting event or activity in hot weather, make sure there are medical services available in case of a heat emergency.
With treatment, you can fully recover from heat exhaustion. Early intervention can also stop it from progressing to heat stroke.
Experiencing a heat stroke is an emergency. If left untreated, it can cause damage to your internal organs, so make sure you take all the precautions not to get a heat stroke.
After you've recovered from heat stroke, you'll probably be more sensitive to high temperatures during the following week. So it's best to avoid hot weather and heavy exercise until your doctor tells you that it's safe to resume your normal activities.