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Everything You Need To Know About Hot Weather (And Extreme Heat) Safety…
Most people cannot wait for the summer months—especially those who live in areas that experience the four seasons rather than two. And while the warmer weather that is the hallmark of the summer season provides much in the way of idea temperatures for many outdoor activities, there are times when the warmer weather can generate dangerous temperature extremes to the point where human health—and life—can be jeopardized. In fact, heat is a major killer among extreme weather phenomena simply because its potential effects are so underestimated (see: “Hundreds Die From Exposure to Heat, Humidity Each Year”).
Even aside from the worst-case scenario—death—during times of prolonged heat, there is still the risk of becoming seriously ill when the body becomes too dehydrated and fatigued during hot weather. This is because excessive heat and prolonged exposure can tax the body’s ability to compensate for the extremely hot weather and properly cool itself off. More to the point, there are two major factors that affect a body's ability to cool itself during extremely hot weather. These factors are:
- High humidity. When the humidity is high, sweat won't evaporate as quickly, which keeps your body from releasing heat as fast as it may need to.
- Personal factors. Age, obesity, fever, dehydration, preexisting medical conditions, sunburn, and prescription drug and alcohol use can play a role in whether a person can cool off enough in very hot weather. People age 65 and older are at high risk for heat-related illnesses. Those who are at highest risk include people 65 and older, children younger than two, and people with chronic diseases or mental illness.
Whenever there is a potential for the air temperature to rise to the point of creating unhealthy conditions, the National Weather Service (NWS) will issue heat-related weather advisories and/or warnings. These weather advisories are based on: (1) the level(s) of heat expected, (2) the potential for the threat to human health, and (3) the length of the period of heat expected. These conditions, in turn are based on what known as the “heat index.”
What is The Heat Index?
During the summer months, meteorologists are often heard invoking what’s known as the “heat index” when measuring conditions that involve high temperatures. The heat index, similar to the “wind chill index” for cold weather, is what the temperature feels like to the human body when relative humidity (the amount of moisture in the air) is combined with the air temperature (sometimes, this is called the feels like temperature).
This index is important, as it is a measure of the comfort level in relation to the human body. When the air temperature begins to warm, our bodies begin to produce swear sweat (or “perspiration”) in order to cool ourselves off (based on the amount of physical activity we are engaging in). As our bodies perspire, the moisture combines with the heat of the air to create an evaporation effect, which effectively reduces the body’s temperature, cooling us off.
But if the feels like temperature (and level of physical exertion) are high enough, it can begin to affect the body’s capacity to cool. At this point, perspiration is not able to evaporate. This occurs because the atmospheric moisture content (i.e. relative humidity) is high, and combines with the heat of the air to lower the amount perspiration from the body. In other words, the human body feels warmer in humid conditions (the opposite is true when the relative humidity decreases because the rate of perspiration increases).
The NWS created the heat index to provide the public with a way to communicate the level of heat and associated unhealthy conditions for particular weather forecast period. By noting the heat index, in conjunction with the forecast for a particular time period (i.e., daily or weekly forecasts), people can plan outdoor activities around these periods of excessive heat.
The upshot is that when the air temperature and relative humidity increase, the heat index increases. And when the heat index increases, the potential for heat-related health risks increases—which also creates the potential for heat emergencies.
What Are Heat Emergencies?
Heat emergencies are health crises caused by exposure to hot weather and sun. Generally, heat emergencies relate to the heath-related illnesses that can result from prolonged exposure (and physical activity) to and in excessive temperatures. Heat emergencies have three stages: heat cramps, heat exhaustion, and heatstroke. All three stages of a heat emergency are serious, with heath stroke being the most serious and life-threatening
Heat cramps are painful, brief muscle cramps that occur during (or shortly after) exercise, work, or (some) other types of physical activity in a hot environment. Heat cramps are exhibited by painful spasms and/or involuntary jerking of the bodies’ muscles. Heat cramps usually involve muscles that are fatigued by heavy work, such as calves, thighs, and shoulders, and usually during a period of engaging in an unaccustomed activity.
Medical professionals believe that heat cramps are due to the depletion of electrolytes in the body due in part to high levels of dehydration. These electrolytes include various essential minerals, such as sodium, potassium, calcium, and magnesium. Changes in the levels of these electrolytes causes suspected chemical changes in the body’s tissues, in turn, causing potential health problems like heat cramps.
In most cases, heat cramps usually end spontaneously in time. However, active intervention with a few simple steps can speed their departure. In most cases, all it takes is resting the body in a cool place, and/or drinking a sports drink containing electrolytes and salt to end a case of heat cramps. Even rehydrating with cool water can remedy this condition in a relatively short amount of time. In lieu of these measures, a simple rehydrating solution consisting of mixing 1/4th to ½ teaspoon of table salt dissolved in a quart (0.95 liter) of water can be used to alleviate heat cramps.
To prevent heath cramps, keep physically-demanding activity to a minimum during particularly hot periods. Eventually, the body will become acclimated to the level of activity in the hot weather. At this point, it will still become necessary to drink adequate levels fluid to keep any potential problems at bay.
Heat exhaustion is a serious heat-related health condition caused exposure to high temperatures, particularly when combined with high humidity, and strenuous physical activity.
The signs and symptoms of heat exhaustion may develop suddenly or over time, especially with prolonged periods of exercise. These symptoms include (but are not limited to): the appearance of small “goose bumps” on the surface of the skin (particularly on cool, moist skin); heavy sweating; a weak rapid pulse; the presence of muscle cramps; headaches; nausea; and low blood pressure upon standing, symbolized by a feeling of dizziness, fatigue, and/or faintness.
Without prompt treatment, heat exhaustion can lead to heatstroke, an even more serious and life-threatening condition. Fortunately, heat exhaustion is preventable. If someone is exhibiting the signs and/or symptoms of a suspected case of heat exhaustion, all activity should cease. At this point, the person(s) experiencing suspected heat exhaustion should be relocated to a cooler location, and begin the rehydration process with by drinking cool water and/or a sports drinks
Contact a physician should the signs or symptoms worsen, or if they don't improve within one hour. Seek immediate medical attention if the body’s temperature reaches 104° F (40° C) or higher.
Heatstroke is the most serious of the potential heat emergencies. It is a condition caused when the body overheats, usually as a result of prolonged exposure and physical exertion in high temperatures. Heat stroke occurs usually when the body’s temperature rises to 104° F (40° C) or higher. Heatstroke requires emergency treatment.
Untreated heatstroke can quickly damage vital organs in the body, including the brain, heart, kidneys, as well as the muscles. The damage worsens the longer treatment is delayed, increasing the risk of serious complications or death. Symptoms of heatstroke include: A high body temperature of 10°4 F (40° C) or greater; a noticeable lack of sweating, despite the temperatures; the presence of skin that feels hot and dry to the touch; the appearance of a red coloring to the skin/flesh; a change in mental behavior, symbolized by confusion, agitation, slurred speech, irritability, and deliriousness; nausea and vomiting; rapid breathing or a shortness of breath; a rapid pulse; a throbbing headache; and/of unconsciousness.
If someone is experiencing suspected case of heatstroke, all efforts should be made to seek immediate medical help for that individual. Call 911 or the nearest local emergency service first responder.
Additionally, take immediate action to cool the overheated person while waiting for emergency treatment. Get the person into shade or indoors. Remove excess clothing. Cool the person’s body down with whatever means available — put them in a cool tub of water or a cool shower, hose them down with water from a garden hose, or place ice packs or cold, wet towels on the person's head, neck, armpits and groin. The overall goal is to cool the person’s body temperature until they can be given primary medical attention.
For those living in areas subject to seasonal extreme—or the occasional unusual period of atypically hot weather, it becomes important to understand the potential risks involved with a heat emergency. What’s more, taking note of weather forecast—especially hot weather—will allow for proper planning during anticipated (and prolonged) periods outdoors. Furthermore, the NWS regularly issues hot weather advisories—that includes the death index—during periods of excessive heat. These hot weather advisories, like the heat index, conveys to the public the particular level of potential hot weather dangers and hazards expected during an advisory forecast period.
Excessive Heat Conditions and Advisories
There are several categories of hot weather advisories that the NWS uses to warn the public of oncoming periods of excessive heat (some of which can be found here, “The Most Commonly-Issued Weather Watches & Warnings - A Glossary”). In most cases, the hot weather advisories tend to be implemented incrementally; that is, they begin with lower level alerts, and graduate to more serious weather warnings—depending on the temperature and conditions. At one level of excessive heat forecasts, there is what’s known as “air-quality alerts.”
No doubt, most people living in urban areas have heard of “air quality days” (also known as “ozone-alert days” or “ozone-action days,” depending on location). These are days that occur during (anticipated) warmer-than-usual weather, where is the air is difficult—or even dangerous—to breathe. This is because the hot weather tends increase the levels of air pollution, affecting the quality of the air that we breathe in and around the alert area, experienced most (but not exclusively) often in cities and major urban areas. In general, two major factors contribute to air pollution that can cause an air quality alert:
- Ground-Level Ozone – High-levels of ground-level ozone are frequently the cause of air quality alerts. Ground-level ozone is created by pollutants such as car exhaust and industrial fumes mixing with oxygen. This most often happens on hot, but dry sunny days with a light breeze. Ground-level ozone can trigger asthma attacks and decrease lung function.
- Particulate Matter – Particulate matter consists of pollutants such as dust, soot, ash and wood smoke. This is often caused by the burning of fossil fuels or other chemical processes. This type of air quality issue is most common on hot, humid days.
To communicate the level of risks associated with these periods of hot weather, forecasters and meteorologists created a color-coded system differentiating the different levels of potential risks to health that a particular “air quality-alert day” may cause (see below).
During more threatening levels of heat, the NWS will begin to issue more urgent excessive heat-related advisories. These advisories, going from least to most critical, include:
- Heat Advisory – The NWS may issue a heat advisory within 12 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this type of advisory is when the maximum heat index temperature is expected to be 100° or higher for at least 2 days, and night time air temperatures will not drop below 75° F (24° C). However, these criteria vary from region to region of the country, especially for areas that are not used to dangerous heat conditions. A heat advisory enables those in the advisory area to plan ahead and take precautions to avoid heat illness.
- Excessive Heat Watch – The NWS will issue an excessive heat watch when the heat index is expected to be greater than 105 °F (41 °C) across the northern regions of the U.S., or when the heat index is expected to reach 110 °F (43 °C) across the southern regions during the day, and/or nighttime low temperature will be at least 75 °F (24 °C) or higher for 2 consecutive days. This means that high heat index values may are expected within 12 hours of the issuance of the watch for the watch area that include significantly above normal temperatures and high humidity levels. An excessive heat watch is an advisory to the public that unhealthy heat-related conditions may arise that can pose a threat to human life through conditions such as heatstroke.
- Excessive Heat Warning – The NWS will issue an excessive heat warning within 12 hours of the heat index reaching one of two criteria levels. In most areas, a warning will be issued if there is a heat index of at least 105 °F for more than 3 hours per day for 2 consecutive days, or if the heat index is greater than 115 °F for any period of time. A warning is an indication that high heat index values are imminent, and are likely to pose a threat to human life through prolonged exposure to such extreme conditions.
In cases of excessive heath watches and warnings, local offices of the NWS, particularly those where excessive heat is less frequent or in areas with deserts or mountainous terrain, often have their own criteria…and may issue their own watch and/or warning for these areas.
But even in the absence of serious or even life-threatening heat emergencies, there are other inherent dangers with prolonged exposure to sunlight (and hot weather). Primary among these other hot weather hazards is the risk for sunburn.
Sunburn is the term for red, sometimes swollen and painful skin caused by the overexposure of unprotected (and bare) skin to ultraviolet (UV) rays from the sun. Cases of sunburn can vary from mild to severe. What’s more, the extent of a particular case of sunburn depends on skin type of the person at risk, the time of day/year the exposure takes place, the amount of exposure to the sun, and even the location and latitude at where the exposure.
People with fair or freckled skin, blond or red hair, and blue eyes usually sunburn easily. While the skin of children younger than 6 and adults older than 60 is more sensitive to sunlight. What’s more, people are likely to get sunburned between 10 am and 4 pm, when the sun's rays are the strongest. What’s more, sunburn is possible even on cloudy days, as the sun's damaging UV light can pass through clouds. It’s also easier to get sunburned at higher altitudes, because there is less of the earth's atmosphere to block the sunlight (UV exposure increases about 4% for every 1000 feet/305 meters gain in elevation.). These primary—as well as lesser factors—can affect the likelihood, frequency, and severity of sunburns.
This means that the physical symptoms of sunburn can vary from person to person. In some individuals, the characteristic redness of the skin may not even be noticeable for several hours after the burn has begun. In others, the skin may begin to turn red in as little as 30 minutes, but most often takes 2 to 6 hours. In most cases, peak redness may begin anywhere from 12 to 24 hours after exposure. And pain is usually most extreme 6 to 48 hours after exposure. The burn continues to develop for 24 to 72 hours following exposure, and usually followed by peeling skin in 3 to 8 days.
Minor sunburns typically cause nothing more than slight redness and tenderness to the affected areas. In more serious cases, blistering can occur. But extreme sunburns can be painful to the point of where even moving can be painful, and may require hospital care. Still, in much more severe cases, symptoms can include fever, chills, nausea and vomiting, weakness and symptoms of shock that can constitute of low blood pressure, fainting and/or extreme weakness.
Sunburns are classified into the same category types are more traditional burns; by degrees.
- First-Degree Sunburn – A first-degree sunburn is skin damage from the sun's UV rays, characterized by mild pain and redness, but which only affects outer layer of skin. The red skin might hurt to the touch. First-degree sunburns are typically mild, and can usually be treated with common home or store-bought remedies.
Second-Degree Sunburn –A second-degree sunburn is skin damage from the sun’s UV rays characterized by red and painful swelling that typically includes blistering. The damage to the skin usually impacts deeper layers of skin, and possibly damage to nerve endings. This type of sunburn is usually more painful and takes longer to heal. Second-Degree sunburn may require medical attention, depending on the severity and length of exposure.
Third-Degree Sunburn – A Third Degree Sunburn, thought very rare, is sunburn damage resulting from prolonged exposure to the sun’s UV rays that affects all layers of skin and can be life threatening of they extend over a large area of skin. It is the most severe degree of sunburn, but it is sometimes least painful owing to the destruction of nerves that is normally associated with it. In a third-degree sunburn, the full skin thickness has to be destroyed as to reach the fatty tissue that lie underneath the skin. Because of its severity and extent of the damage involved, third-degree sunburns require immediate medical attention. But even treated, third-degree sunburns may leave permanent scarring.
The best way to prevent sunburn is to limit the skin’s unprotected exposure to the sun. The best way to accomplish this is by practicing the following hot weather habits:
- Avoid sun-exposure during the midday sun (from 10 in the morning to 4 in the afternoon), which is the strongest sunlight.
- If outdoors, try work or otherwise confine activities to shaded areas. Cover exposed parts of the body with a wide-brimmed hat that covers the neck, ears, eyes, and head (scalp). Also, wearing sunglasses with can prevent sun damage to the eyes. Wear
- Wear loose-fitting, tightly-woven clothing that covers the arms and legs. Additionally, consider wearing clothing made of sun-protective fabrics (these clothes have a special label that indicates to the wearer how effective they are in protecting the skin from UV rays).
- Above all, apply a sunscreen. Sunscreens are products combining several ingredients that help prevent the sun's ultraviolet (UV) radiation from reaching and damaging the skin. They can be purchased in lotions, gels, creams, ointments, and spray forms. Sunscreens with a “sun-protection factor” (SPF) of 30 or higher offer the best protection. However, a sunscreen’s effectiveness can be reduced by sweat, or if the sin is exposed to water, so it may become necessary to reapply the sunscreen regularly during prolonged periods of sun exposure (sunscreens labeled "water-resistant" are made to protect people while they are swimming or sweating. However, “water-resistant” does not mean “water-proof,” hence, the need to reapply sunscreen when the skin occasionally in and around water).
- Use lip balm or cream that has SPF of 30 or higher to protect your lips from getting sunburned.
Summer, like most other seasons, has its own periods of extreme weather conditions. And like most other forms of extreme weather, planning ahead and applying a proactive stance to safety can go a long ways towards preventing both short- and long-term repercussions that arise from extreme weather events. When it comes to extreme temperatures, knowing what the potential hazards are, and how to mitigate these hazards can ensure a relatively safe and uneventful summer season.
- The No-Nonsense Guide To Heat Wave, Drought, & Hot Weather Safety (Enhanced Edition) by Jeffery
Publications like the "No-Nonsense Guide To Heat Wave, Drought, & Hot Weather Safety" can provide even more safety tips--as well as more information on how to stay safe in hot weather. Also in e-book format
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