(Disaster Manual/1. Disaster/Heat wave)
What Is Extreme Heat?
Conditions of extreme heat are defined as summertime temperatures that are substantially hotter and/or more humid than average for location at that time of year. Humid or muggy conditions, which add to the discomfort of high temperatures, occur when a “dome” of high atmospheric pressure traps hazy, damp air near the ground. Extremely dry and hot conditions can provoke dust storms and low visibility. Droughts occur when a long period passes without substantial rainfall. A heat wave combined with a drought is a very dangerous situation.
Heat Waves and Energy Crunches: the Future is Now
Alex Steffen, 16 Jul 2010
Two stories I came across yesterday struck me as particularly indicative of the gulf between the speed at which global change is unfolding and our perceptions of the urgency of the issues. There’s often a presumption that we have decades to change (so change can begin gradually) and decades more before we have to worry about impacts. The evidence, though, increasingly points to a much shorter horizon for action and adaptation.
1. The first story reports on a big Stanford study which combined the latest suite of climate models to understand how climate change already under way is likely to affect the hottest extremes of weather in the Western U.S.: “The results were surprising. According to the climate models, an intense heat wave — equal to the longest on record from 1951 to 1999 — is likely to occur as many as five times between 2020 and 2029 over areas of the western and central United States.
The Stanford team also forecast a dramatic spike in extreme seasonal temperatures during the current decade. Temperatures equaling the hottest season on record from 1951 to 1999 could occur four times between now and 2019 over much of the U.S., according to the researchers.
The 2020s and 2030s could be even hotter, particularly in the American West. From 2030 to 2039, most areas of Utah, Colorado, Arizona and New Mexico could endure at least seven seasons equally as intense as the hottest season ever recorded between 1951 and 1999, the researchers concluded.
The mean global temperature in 30 years would be about 3.6 degrees F (2 degrees C) hotter than in the pre-industrial era of the 1850s.
Many climate scientists and policymakers have targeted a 2-degree C temperature increase as the maximum threshold beyond which the planet is likely to experience serious environmental damage, the study says.
“Frankly, I was expecting that we’d see large temperature increases later this century with higher greenhouse gas levels and global warming,” Diffenbaugh said. “I did not expect to see anything this large within the next three decades. This was definitely a surprise.”
2. The second story told of a new report from the venerable insurance company Lloyd’s of London and the Royal Institute of International Affairs (often called Chatham House) finding that Peak Oil, rising global demand for energy and the need for emissions reductions (not to mention the vulnerability of energy infrastructure to climate change and political turmoil) are very likely to bring big shifts in energy prices in the relatively short term: The review is groundbreaking because it comes from the heart of the City and contains the kind of dire warnings that are more associated with environmental groups or others accused by critics of resorting to hype. It takes a pot shot at the International Energy Agency which has been under fire for apparently under-estimating the threats, noting: “IEA expectations [on crude output] over the last decade have generally gone unmet.”
The report the world is heading for a global oil supply crunch and high prices owing to insufficient investment in oil production plus a rebound in global demand following recession. It repeats warning from Professor Paul Stevens, a former economist from Dundee University, at an earlier Chatham House conference that lack of oil by 2013 could force the price of crude above $200 a barrel.
Both of these studies bear further examination and debate, of course, but the overall trend which I see them contributing to has become increasingly clear: a growing chorus of those tasked most explicitly with responsibility for our future — doctors, generals, diplomats, scientists — all telling us that when it comes to planetary crisis, the future is now.
Contrast that urgency with the political debate in most countries. What we see is an appalling gap between our elected leaders’ perception that these are problems for future generations to solve and the reality that we’re already dealing with them today.
There’s a quote that’s been bouncing around the Worldchanging office recently: “When there’s a gap between perception and reality, more reality won’t close the gap.” The gap between the political perception of our problems being slow and distant and the reality of acceleration and imminence points again at the importance of stories that help change our perspectives on scope, scale and speed.
Extreme Heat: Know the Terms (see section, E. Hot Weather Health Emergencies, below)
• Heat Wave: A prolonged period of excessive heat, often combined with excessive humidity.
• Heat Index: A number in degrees Fahrenheit (F) that tells how hot it feels when relative humidity is added to the air temperature. Exposure to full sunshine can increase the heat index by 15 degrees.
• Heat Cramps: Muscular pains and spasms due to heavy exertion. Although heat cramps are the least severe, they are often the first signal that the body is having trouble with the heat.
• Heat Exhaustion: Typically occurs when people exercise heavily or work in a hot, humid place where body fluids are lost through heavy sweating. Blood flow to the skin increases, causing blood flow to decrease to the vital organs. This results in a form of mild shock. If not treated, the victim’s condition will worsen. Body temperature will keep rising and the victim may suffer heat stroke.
• Heat Stroke: A life-threatening condition. The victim’s temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly.
• Sun Stroke: Another term for heat stroke.
A. Before Extreme Heat
To prepare for extreme heat, you should:
• Install window air conditioners snugly; insulate if necessary.
• Check air-conditioning ducts for proper insulation.
• Install temporary window reflectors (for use between windows and drapes), such as aluminum foil-covered cardboard, to reflect heat back outside.
• Weather-strip doors and sills to keep cool air in.
• Cover windows that receive morning or afternoon sun with drapes, shades, awnings, or louvers. (Outdoor awnings or louvers can reduce the heat that enters a home by up to 80 percent.)
• Keep storm windows up all year.
Pasted from <http://www.fema.gov/hazard/heat/heat_before.shtm>
B. During a Heat Emergency
What you should do if the weather is extremely hot:
• Stay indoors as much as possible and limit exposure to the sun. Stay in the shade when possible, and avoid prolonged sun exposure during the hottest part of the day, between 10:00 a.m. and 4:00 p.m. I know you may want to get a tan.. but trust me, you look just fine the way you are. Skin cancer is not worth it, also tanning speeds up the aging process of your skin.
• Use sunscreen with an SPF (sun protection factor) of about 50—even on cloudy days. Apply a liberal amount of sunscreen at least 30 minutes before going outside. Reapply sunscreen every two hours, or after swimming or sweating.
• Stay on the lowest floor out of the sunshine if air conditioning is not available.
• Consider spending the warmest part of the day in public buildings such as libraries, schools, movie theaters, shopping malls, and other community facilities. Circulating air can cool the body by increasing the perspiration rate of evaporation.
• Eat small meals of carbohydrates, salads and fruit, and eat more often. Avoid foods that are high in protein, because they increase metabolic heat. This will help your body regulate in the heat easier.
• Avoid using salt tablets unless directed to do so by a physician.
• Drink plenty of water. Carry water or juice with you and drink continuously even if you don’t feel thirsty. Injury and death can occur from dehydration, which can happen quickly and unnoticed. Symptoms of dehydration are often confused with other causes. Your body needs water to keep cool. Water is the safest liquid to drink during heat emergencies. This is especially true in an emergency.
• Keep water in your vehicle.
• Avoid drinks with alcoholic or caffeine. They can make you feel good briefly, but make the heat’s effects on your body worse. This is especially true about beer, which actually dehydrates the body. People who are on fluid-restrictive diets or who have a problem with fluid retention should consult their doctor before increasing liquid intake.
• Wear loose, lightweight, light-colored clothing. Light colors reflect heat and sunlight and help you maintain a normal body temperature. Cover as much skin as possible to avoid sunburn and over-warming effects of sunlight on your body. Keep direct sunlight off your face by wearing a wide-brimmed hat. Sunlight can burn and warm and inner core of your body. Also use umbrellas and sunglasses to shield against the sun’s rays. keep a form of shade shelter in your car such as a tube tent for emergencies.
• Check on family, friends, and neighbors who do not have air conditioning and who spend much of their time alone.
• Never leave children or pets alone in closed vehicles.
• Avoid strenuous work during the warmest part of the day. Use a buddy system when working in extreme heat, and take frequent breaks. If you must engage in strenuous activity, do so during the coolest part of the day, which is usually in the morning between 4:00 a.m. and 7:00 a.m. Try to do outside yard work during these early cool hours or at dusk when the sun is not directly on you.
• Change into dry clothing if your clothes become saturated with sweat.
An emergency water shortage can be caused by prolonged drought, poor water supply management, or contamination of a surface water supply source or aquifer.
Drought can affect vast territorial regions and large population numbers. Drought also creates environmental conditions that increasethe risk of other hazards such as fire, flash flood, and possible landslides and debris flow. Conserving water means more water available for critical needs for everyone.
Pasted from <http://www.fema.gov/hazard/heat/heat_during.shtm>
C. Extreme Heat: A Prevention Guide to Promote Your Personal Health and Safety
• Elderly people (65 years and older), infants and children and people with chronic medical conditions are more prone to heat stress.
• Air-conditioning is the number one protective factor against heat-related illness and death. During conditions of extreme heat, spend time in locations with air-conditioning such as shopping malls, public libraries, or public health sponsored heat-relief shelters in your area.
• Get informed. Listen to local news and weather channels or contact your local public health department during extreme heat conditions for health and safety updates
• Drink cool, nonalcoholic beverages and increase your fluid intake, regardless of your activity level.
Heat related notes
1. Heat-related deaths and illness are preventable yet annually many people succumb to extreme heat. Historically, from 1979-2003, excessive heat exposure caused 8,015 deaths in the United States. During this period, more people in this country died from extreme heat than from hurricanes, lightning, tornadoes, floods, and earthquakes combined. In 2001, 300 deaths were caused by excessive heat exposure.
2. People suffer heat-related illness when their bodies are unable to compensate and properly cool themselves. The body normally cools itself by sweating. But under some conditions, sweating just isn’t enough. In such cases, a person’s body temperature rises rapidly. Very high body temperatures may damage the brain or other vital organs.
3. Several factors affect the body’s ability to cool itself during extremely hot weather. When the humidity is high, sweat will not evaporate as quickly, preventing the body from releasing heat quickly. Other conditions related to risk include age, obesity, fever, dehydration, heart disease, mental illness, poor circulation, sunburn, and prescription drug and alcohol use.
4. Because heat-related deaths are preventable, people need to be aware of who is at greatest risk and what actions can be taken to prevent a heat-related illness or death. The elderly, the very young, and people with mental illness and chronic diseases are at highest risk. However, even young and healthy individuals can succumb to heat if they participate in strenuous physical activities during hot weather. 5. Air-conditioning is the number one protective factor against heat-related illness and death. If a home is not air-conditioned, people can reduce their risk for heat-related illness by spending time in public facilities that are air-conditioned.
6. Summertime activity, whether on the playing field or the construction site, must be balanced with measures that aid the body’s cooling mechanisms and prevent heat-related illness. This pamphlet tells how you can prevent, recognize, and cope with heat-related health problems.
D. During Hot Weather
To protect your health when temperatures are extremely high, remember to keep cool and use common sense. The following tips are important:
1. Drink Plenty of Fluids: During hot weather you will need to increase your fluid intake, regardless of your activity level. Don’t wait until you’re thirsty to drink. During heavy exercise in a hot environment, drink two to four cup/glasses (16-32 ounces) of cool fluids each hour.
Don’t drink liquids that contain alcohol, or large amounts of sugar—these actually cause you to lose more body fluid. Also avoid very cold drinks, because they can cause stomach cramps.
2. Replace Salt and Minerals: Heavy sweating removes salt and minerals from the body. These are necessary for your body and must be replaced. If you must exercise, drink two to four glasses of cool, non-alcoholic fluids each hour. A sports beverage can replace the salt and minerals you lose in sweat. However, if you are on a low-salt diet, talk with your doctor before drinking a sports beverage or taking salt tablets.
3. Wear Appropriate Clothing and Sunscreen: Wear as little clothing as possible when you are at home. Choose lightweight, light-colored, loose-fitting clothing. Sunburn affects your body’s ability to cool itself and causes a loss of body fluids. It also causes pain and damages the skin. If you must go outdoors, protect yourself from the sun by wearing a wide-brimmed hat (also keeps you cooler) along with sunglasses, and by putting on sunscreen of SPF 15 or higher (the most effective products say “broad spectrum” or “UVA/UVB protection” on their labels) 30 minutes prior to going out. Continue to reapply it according to the package directions.
4. Schedule Outdoor Activities Carefully: If you must be outdoors, try to limit your outdoor activity to morning and evening hours. Try to rest often in shady areas so that your body’s thermostat will have a chance to recover.
5. Pace Yourself: If you are not accustomed to working or exercising in a hot environment, start slowly and pick up the pace gradually. If exertion in the heat makes your heart pound and leaves you gasping for breath, STOP all activity. Get into a cool area or at least into the shade, and rest, especially if you become lightheaded, confused, weak, or faint.
6. Stay Cool Indoors: Stay indoors and, if at all possible, stay in an air-conditioned place. If your home does not have air conditioning, go to the shopping mall or public library—even a few hours spent in air conditioning can help your body stay cooler when you go back into the heat. Call your local health department to see if there are any heat-relief shelters in your area. Electric fans may provide comfort, but when the temperature is in the high 90s, fans will not prevent heat-related illness. Taking a cool shower or bath or moving to an air- conditioned place is a much better way to cool off. Use your stove and oven less to maintain a cooler temperature in your home
7. Use a Buddy System: When working in the heat, monitor the condition of your co-workers and have someone do the same for you. Heat-induced illness can cause a person to become confused or lose consciousness. If you are 65 years of age or older, have a friend or relative call to check on you twice a day during a heat wave. If you know someone in this age group, check on them at least twice a day.
8. Monitor Those at High Risk: Although anyone at any time can suffer from heat-related illness, some people are at greater risk than others.
• Infants and young children are sensitive to the effects of high temperatures and rely on others to regulate their environments and provide adequate liquids.
• People 65 years of age or older may not compensate for heat stress efficiently and are less likely to sense and respond to change in temperature.
• People who are overweight may be prone to heat sickness because of their tendency to retain more body heat.
• People who overexert during work or exercise may become dehydrated and susceptible to heat sickness.
• People who are physically ill, especially with heart disease or high blood pressure, or who take certain medications, such as for depression, insomnia, or poor circulation, may be affected by extreme heat.
• Visit adults at risk at least twice a day and closely watch them for signs of heat exhaustion or heat stroke. Infants and young children, of course, need much more frequent watching.
• Adjust to the Environment: Be aware that any sudden change in temperature, such as an early summer heat wave, will be stressful to your body. You will have a greater tolerance for heat if you limit your physical activity until you become accustomed to the heat. If you travel to a hotter climate, allow several days to become acclimated before attempting any vigorous exercise, and work up to it gradually
Do Not Leave Children in Cars
Even in cool temperatures, cars can heat up to dangerous temperatures very quickly. Even with the windows cracked open, interior temperatures can rise almost 20 degrees Fahrenheit within the first 10 minutes. Anyone left inside is at risk for serious heat-related illnesses or even death. Children who are left unattended in parked cars are at greatest risk for heat stroke, and possibly death. When traveling with children, remember to do the following:
• Never leave infants, children or pets in a parked car, even if the windows are cracked open.
• To remind yourself that a child is in the car, keep a stuffed animal in the car seat. When the child is buckled in, place the stuffed animal in the front with the driver.
• When leaving your car, check to be sure everyone is out of the car. Do not overlook any children who have fallen asleep in the car.
Use Common Sense
Remember to keep cool and use common sense:
• Avoid hot foods and heavy meals—they add heat to your body.
• Drink plenty of fluids and replace salts and minerals in your body. Do not take salt tablets unless under medical supervision.
• Dress infants and children in cool, loose clothing and shade their heads and faces with hats or an umbrella.
• Limit sun exposure during mid-day hours and in places of potential severe exposure such as beaches.
• Do not leave infants, children, or pets in a parked car.
• Provide plenty of fresh water for your pets, and leave the water in a shady area.
E. Hot Weather Health Emergencies
Even short periods of high temperatures can cause serious health problems. During hot weather health emergencies, keep informed by listening to local weather and news channels or contact local health departments for health and safety updates. Doing too much on a hot day, spending too much time in the sun or staying too long in an overheated place can cause heat-related illnesses. Know the symptoms of heat disorders and overexposure to the sun, and be ready to give first aid treatment.
Extreme Heat Protection
Extreme heat exposure occurs when the body’s temperature cannot maintain a normal temperature. Usually sweating will cool the body but sometimes it is not enough. Brain damage and organ damage can happen if the body temperature remains too high for too long. When humidity is high, sweat cannot evaporate quickly enough and prevents the body from releasing heat.
Heat stroke occurs when the body is unable to regulate its temperature. The body’s temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. Body temperature may rise to 106°F or higher within 10 to 15 minutes. Heat stroke can cause death or permanent disability if emergency treatment is not provided.
Recognizing Heat Stroke
Warning signs of heat stroke vary but may include the following:
• An extremely high body temperature (above 103°F, orally)
• Red, hot, and dry skin (no sweating)
• Rapid, strong pulse
• Lightweight clothing
• Throbbing headache
What to Do
If you see any of these signs, you may be dealing with a life-threatening emergency. Have someone call for immediate medical assistance while you begin cooling the victim. Do the following:
• Get the victim to a shady area.
• Cool the victim rapidly using whatever methods you can. For example, immerse the victim in a tub of cool water; place the person in a cool shower; spray the victim with cool water from a garden hose; sponge the person with cool water; or if the humidity is low, wrap the victim in a cool, wet sheet and fan him or her vigorously.
• Monitor body temperature, and continue cooling efforts until the body temperature drops to 101-102°F.
• If emergency medical personnel are delayed, call the hospital emergency room for further instructions.
• Do not give the victim fluids to drink.
• Get medical assistance as soon as possible.
• Sometimes a victim’s muscles will begin to twitch uncontrollably as a result of heat stroke. If this happens, keep the victim from injuring himself, but do not place any object in the mouth and do not give fluids. If there is vomiting, make sure the airway remains open by turning the victim on his or her side.
Heat exhaustion is a milder form of heat-related illness that can develop after several days of exposure to high temperatures and inadequate or unbalanced replacement of fluids. It is the body’s response to an excessive loss of the water and salt contained in sweat. Those most prone to heat exhaustion are elderly people, people with high blood pressure, and people working or exercising in a hot environment.
Recognizing Heat Exhaustion
Warning signs of heat exhaustion include the following:
• Heavy sweating
• Muscle cramps
• Nausea or vomiting
The skin may be cool and moist. The victim’s pulse rate will be fast and weak, and breathing will be fast and shallow. If heat exhaustion is untreated, it may progress to heat stroke. Seek medical attention immediately if any of the following occurs:
• Symptoms are severe
• The victim has heart problems or high blood pressure. Otherwise, help the victim to cool off, and seek medical attention if symptoms worsen or last longer than 1 hour.
What to Do
Cooling measures that may be effective include the following:
• Cool, nonalcoholic beverages
• An air-conditioned environment
• Lightweight clothing
• Cool shower, bath, or sponge bath
Heat cramps usually affect people who sweat a lot during strenuous activity. This sweating depletes the body’s salt and moisture. The low salt level in the muscles may be the cause of heat cramps. Heat cramps may also be a symptom of heat exhaustion.
Recognizing Heat Cramps
Heat cramps are muscle pains or spasms—usually in the abdomen, arms, or legs—that may occur in association with strenuous activity. If you have heart problems or are on a low-sodium diet, get medical attention for heat cramps.
What to Do
If medical attention is not necessary, take these steps:
• Stop all activity, and sit quietly in a cool place.
• Drink clear juice or a sports beverage.
• Do not return to strenuous activity for a few hours after the cramps subside, because further exertion may lead to heat exhaustion or heat stroke.
•Seek medical attention for heat cramps if they do not subside in 1 hour.
Sunburn should be avoided because it damages the skin. Although the discomfort is usually minor and healing often occurs in about a week, a more severe sunburn may require medical attention.
Symptoms of sunburn are well known: the skin becomes red, painful, and abnormally warm after sun exposure.
What to Do
Consult a doctor if the sunburn affects an infant younger than 1 year of age or if these symptoms are present:
• Fluid-filled blisters
• Severe pain
Also, remember these tips when treating sunburn:
• Avoid repeated sun exposure.
• Apply cold compresses or immerse the sunburned area in cool water.
• Apply moisturizing lotion to affected areas. Do not use salve, butter, or ointment.
• Do not break blisters.
Heat rash is a skin irritation caused by excessive sweating during hot, humid weather. It can occur at any age but is most common in young children.
Recognizing Heat Rash
Heat rash looks like a red cluster of pimples or small blisters. It is more likely to occur on the neck and upper chest, in the groin, under the breasts, and in elbow creases.
What to Do
The best treatment for heat rash is to provide a cooler, less humid environment. Keep the affected area dry. Dusting powder may be used to increase comfort.
Treating heat rash is simple and usually does not require medical assistance. Other heat-related problems can be much more severe.
F. Heat Stress in the Elderly
Elderly people (that is, people aged 65 years and older) are more prone to heat stress than younger people for several reasons:
• Elderly people do not adjust as well as young people to sudden changes in temperature.
• They are more likely to have a chronic medical condition that changes normal body responses to heat.
• They are more likely to take prescription medicines that impair the body’s ability to regulate its temperature or that inhibit perspiration.