It is the Heat... and the Humidity.
Many parts of the country are beginning to suffer a "heat wave." This being summer, wherever you are there are going to be dangerously hot days.
Heat waves cause many excess deaths and suffering, most of them unreported as such. Heat waves in the U.S. cause more deaths than hurricanes, lightning, tornadoes, floods, and earthquakes combined!
From 1999–2003, the U.S officially had a total of 3,442 reported heat-related deaths, for an annual mean of 688. In 2003, Europe suffered 34,000 excess deaths do to a heat wave.
Yet they are a silent killer with relatively less public attentiond paid. They cause relatively little damage to infrastructure and offer no dramatic pictures for TV news. Many deaths go unreported or unattributed. And yet everyone of these deaths is preventable!
This diary offers both personal and community advice as to how to protect yourself, and some political context (yup. everything has a political context).
1. How to Protect Yourself
If it is above average heat, take precautions, even if it is not officially declared a heat emergency. Above average heat is when it is more then 10 degrees above average for three days in a row; that is when deaths start increasing. To protect your health when temperatures are extremely high, remember to keep cool and use common sense.
In addition to the heat per se, the humidity contributes to your body's inability to cool itself. Sweating only will work to cool yourself if it can evaporate easily off your skin. It is the evaporation that cools you. When it is humid, the sweat cannot do it evaporative cooling. Hence 90s in the midwest or northeast are as bad or worse then the low 100s in the southwest. Of course if it is too hot (hello Austin in the summer) it does not matter if it is humid or not; when it get into the 100s or 1-teens in the southwest deaths go up there too.
The following tips are important for all of us (additional information for the hot workplace is here). More info is available here, and as pamphlets and in multiple languages (English, Spanish, French, Hatain Creole, German, Chinese, Vietnamese)
The #1 Duh! If at all possible, stay indoors in artificially cooled environment. In other words, air conditioning.
(I am quoting this public pamphlet from CDC at length; I helped write the 1991 version of it)
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.
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.
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. 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. Hang out in the mall. Sometimes they will open up the schools or gym or public library.
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.
What Is Extreme Heat?
Temperatures that hover 10 degrees or more above the average high temperature.... 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. Excessively 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.
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:
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.
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 glasses (16-32 ounces) of cool fluids each hour.
Warning: If your doctor generally limits the amount of fluid you drink or has you on water pills, ask how much you should drink while the weather is hot. (e.g. if you have congestive heart failure)
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.
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.
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.
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.
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.
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.
Monitor Those at High Risk
Although any one at any time can suffer from heat-related illness, some people are at greater risk than others.
- Infants and children up to four years of age 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. Farm workers, construction workers, anybody who "has" to work outdoors despite high temperature conditions.
- 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.
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.
Hot Weather Health Emergencies
Even short periods of high temperatures can cause serious health problems. 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.
Heat Stroke
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
Throbbing headache
Dizziness
Nausea
Confusion
Unconsciousness
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
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
Paleness
Muscle cramps
Tiredness
Weakness
Dizziness
Headache
Nausea or vomiting
Fainting
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
Rest
Cool shower, bath, or sponge bath
An air-conditioned environment
Lightweight clothing
Heat Cramps
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
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.
Recognizing Sunburn
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:
Fever
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
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.
2. Politics of Heat Wave and Heat-related Death:
Ever since we first started studying heat waves as a public health issue, which was not until the early 1980s, it has been obvious that the poor suffer the most. There are multiple reasons for this.
People who have to work outdoors, even when it is extra hot out, tend to be poor or lower working class (farm worker, road construction) and without union protection.
Poor and homeless are less likely to have air conditioning. Even poor with places to live are less likely to have air conditioning due to the expense. Just fans don't work, since blow hot moist air does not help cool you. You are not able to evaporate the sweat off yourself. You remain hot and get overheated. In hot dry environments, such as in the southwest, so called swamp coolers (evaporative heaters) can work to some limited degree. But there is no substitute for real air conditioning.
Obviously the homeless on the street are most susceptible.
In some place, the "city father" or other powers that be, have been reluctant to make air conditioned environments (malls, libraries, public schools and gymnasiums) open to the public, have been slow to help get the poor, homeless, mentally ill, elderly, etc. into cooled environments. We have moved from a politicis of not giving a damn to having Heat Wave Response Plans as a specific and real part of national and local emergency preparedness, right up there with other natural disasters and terrorism.
Infamous recent heat waves have included St. Louis in 1980, Phoenix in 1991, Philadelphia in 1993, and especially Chicago in 1995 and Europe (especially France) in 2003.
In addition to heat stroke, many more excess deaths occur during heat waves that are attributed to heart (cardiovascular) causes. Individually, these may not seem connected to the heat wave, but there is a spike in their number and rate that occurs with heat waves, typically with a 2-3 day lag time.
And yes, it is definitely going to be worse in the U.S. with global climate chage. For example, a July hot day in Atlanta that would have a heat index today of 105°F, is expected to reach a heat index of 115°F in the Hadley model, and 130°F in the Canadian model.
Cities and climate are coevolving in a manner that will place more populations at risk:
Cities in general suffer what is referred to as the heat island effect, and are typically 7-12 degrees F hotter then their suburban or rural surroundings. This is due to the combined effect of the high thermal mass provided by concrete and blacktop roads, and the low ventilation ability of the urban "canyons" created by tall buildings.
Worlwide people are moving from rural areas to cities. Developmental change and population increase accompanied with rapid urbanization is quickly transitioning communities from native vegetation to an engineered infrastructure that increases thermal-storage capacity, resulting in significant change in the urban climate compared to adjacent rural regions. Thus more people are susceptible to ever worsening urban heat island effects worldwide.
Worldwide more people are living in cities and are susceptible to these urbanization effects, and of course worldwide most city dwellers do not have access to air conditioning.
Increased demand for air conditioning contributes to electrical demand with secondary effects such as global climate change.
How we build urban areas is also a series of policy and political choices. For example, within a city, residential neighborhoods with greenspace (parks and sidewalks with grass & trees) were cooler then those without, even where the residential buildings (height and density) were similar. More on what you and your communities can do about this is available from EPA.
We can now predict ahead of time, which neighborhoods within a polity are more suscptible to deaths during heat waves. Everyone of these deaths is preventable.
There is a nice public domain PowerPoint slide set covering much of this available here.
The "Excess Heat Events guidebook is available from EPA and additional information is available from EPA and from NOAA.
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