Heat waves are the most lethal type of weather phenomenon in the United States. Between 1992 and 2001, deaths from excessive heat in the United States numbered 2,190, compared with 880 deaths from floods and 150 from hurricanes.[26] The average annual number of fatalities directly attributed to heat in the United States is about 400.[27] The 1995 Chicago heat wave, one of the worst in US history, led to approximately 739 heat-related deaths over a period of 5 days.[28] Eric Klinenberg has noted that in the United States, the loss of human life in hot spells in summer exceeds that caused by all other weather events combined, including lightning, rain, floods, hurricanes, and tornadoes.[29][30] Despite the dangers, Scott Sheridan, professor of geography at Kent State University, found that less than half of people 65 and older abide by heat-emergency recommendations such as drinking plenty of water. In his study of heat-wave behavior, focusing particularly on seniors in Philadelphia, Phoenix, Toronto, and Dayton, Ohio, he found that people over 65 "don't consider themselves seniors." One of his older respondents said: "Heat doesn't bother me much, but I worry about my neighbors."[31]
According to the Agency for Health care Research and Quality, about 6,200 Americans are hospitalized each summer due to excessive heat, and those at highest risk are poor, uninsured or elderly.[32] More than 70,000 Europeans died as a result of the 2003 European heat wave.[33] Also more than 2,000 people died in Karachi, Pakistan in June 2015 due to a severe heat wave with temperatures as high as 49 °C (120 °F).[34][35]
Our concern now is focusing on predicting the future likelihood of heat waves and their severity. In addition, because in most of the world most of those suffering the impacts of a heat wave will be inside a building, and this will modify the temperatures they are exposed to, there is the need to link climate models to building models. This means producing example time series of future weather.[36][37] Other work has shown that future mortality due to heat waves could be reduced if buildings were better designed to modify the internal climate, or if the occupants were better educated about the issues, so they can take action in time.[38][39]
The number of heat fatalities is likely highly underreported due to a lack of reports and misreports.[27] Part of the mortality observed during a heat wave, however, can be attributed to a so-called "harvesting effect", a term for a short-term forward mortality displacement. It has been observed that for some heat waves, there is a compensatory decrease in overall mortality during the subsequent weeks after a heat wave. Such compensatory reductions in mortality suggest that heat affects especially those so ill that they "would have died in the short term anyway".[40]
Another explanation for underreporting is the social attenuation in most contexts of heat waves as a health risk. As shown by the deadly French heat wave in 2003, heat wave dangers result from the intricate association of natural and social factors.[41]
In addition to physical stress, excessive heat causes psychological stress, to a degree which affects performance, and is also associated with an increase in violent crime.[42] High temperatures are associated with increased conflict both at the interpersonal level and at the societal level. In every society, crime rates go up when temperatures go up, particularly violent crimes such as assault, murder, and rape. Furthermore, in politically unstable countries, high temperatures are an aggravating factor that lead toward civil wars.[43]
Additionally, high temperatures have a significant effect on income. A study of counties in the United States found that economic productivity of individual days declines by about 1.7% for each degree Celsius above 15 °C (59 °F).[44]
Abnormally hot temperatures can cause electricity demand to increase during the peak summertime hours of 4 to 7 p.m. when air conditioners are straining to overcome the heat. If a hot spell extends to three days or more, however, nighttime temperatures do not cool down, and the thermal mass in homes and buildings retains the heat from previous days. This heat build-up causes air conditioners to turn on earlier and to stay on later in the day. As a result, available electricity supplies are challenged during a higher, wider, peak electricity consumption period.[citation needed]
Heat waves often lead to electricity spikes due to increased air conditioning use, which can create power outages, exacerbating the problem. During the 2006 North American heat wave, thousands of homes and businesses went without power, especially in California. In Los Angeles, electrical transformers failed, leaving thousands without power for as long as five days.[45] The 2009 South Eastern Australia Heat Wave caused the city of Melbourne, Australia to experience some major power disruptions which left over half a million people without power as the heat wave blew transformers and overloaded a power grid.
If a heat wave occurs during a drought, wh
Heat edema presents as a transient swelling of the hands, feet, and ankles and is generally secondary to increased aldosterone secretion, which enhances water retention. When combined with peripheral vasodilation and venous stasis, the excess fluid accumulates in the dependent areas of the extremities. The heat edema usually resolves within several days after the patient becomes acclimated to the warmer environment. No treatment is required, although wearing support stockings and elevating the affected legs will help minimize the edema.
Heat rash, also known as prickly heat, is a maculopapular rash accompanied by acute inflammation and blocked sweat ducts. The sweat ducts may become dilated and may eventually rupture, producing small pruritic vesicles on an erythematous base. Heat rash affects areas of the body covered by tight clothing. If this continues for a duration of time it can lead to the development of chronic dermatitis or a secondary bacterial infection. Prevention is the best therapy. It is also advised to wear loose-fitting clothing in the heat. However, once heat rash has developed, the initial treatment involves the application of chlorhexidine lotion to remove any desquamated skin. The associated itching may be treated with topical or systemic antihistamines. If infection occurs a regimen of antibiotics is required.
Heat cramps are painful, often severe, involuntary spasms of the large muscle groups used in strenuous exercise. Heat cramps tend to occur after intense exertion. They usually develop in people performing heavy exercise while sweating profusely and replenishing fluid loss with non-electrolyte containing water. This is believed to lead to hyponatremia that induces cramping in stressed muscles. Rehydration with salt-containing fluids provides rapid relief. Patients with mild cramps can be given oral .2% salt solutions, while those with severe cramps require IV isotonic fluids. The many sport drinks on the market are a good source of electrolytes and are readily accessible.
Heat syncope is related to heat exposure that produces orthostatic hypotension. This hypotension can precipitate a near-syncopal episode. Heat syncope is believed to result from intense sweating, which leads to dehydration, followed by peripheral vasodilation and reduced venous blood return in the face of decreased vasomotor control. Management of heat syncope consists of cooling and rehydration of the patient using oral rehydration therapy (sport drinks) or isotonic IV fluids. People who experience heat syncope should avoid standing in the heat for long periods of time. They should move to a cooler environment and lie down if they recognize the initial symptoms. Wearing support stockings and engaging in deep
Heat syncope is related to heat exposure that produces orthostatic hypotension. This hypotension can precipitate a near-syncopal episode. Heat syncope is believed to result from intense sweating, which leads to dehydration, followed by peripheral vasodilation and reduced venous blood return in the face of decreased vasomotor control. Management of heat syncope consists of cooling and rehydration of the patient using oral rehydration therapy (sport drinks) or isotonic IV fluids. People who experience heat syncope should avoid standing in the heat for long periods of time. They should move to a cooler environment and lie down if they recognize the initial symptoms. Wearing support stockings and engaging in deep knee-bending movements can help promote venous blood return.
Heat exhaustion is considered by experts to be the forerunner of heat stroke (hyperthermia). It may even resemble heat stroke, with the difference being that the neurologic function remains intact. Heat exhaustion is marked by excessive dehydration and electrolyte depletion. Symptoms may include diarrhea, headache, nausea and vomiting, dizziness, tachycardia, malaise, and myalgia. Definitive therapy includes removing patients from the heat and replenishing their fluids. Most patients will require fluid replacement with IV isotonic fluids at first. The salt content is adjusted as necessary once the electrolyte levels are known. After discharge from the hospital, patients are instructed to rest, drink plenty of fluids for 2–3 hours, and avoid the heat for several days. If this advice is not followed it may then lead to heat stroke.
One public health measure taken during heat waves is the setting-up of air-conditioned public cooling centers.
Heat waves are the most lethal type of weather phenomenon in the United States. Between 1992 and 2001, deaths from excessive heat in the United States numbered 2,190, compared with 880 deaths from floods and 150 from hurricanes.[26] The average annual number of fatalities directly attributed to heat in the United States is about 400.[27] The 1995 Chicago heat wave, one of the worst in US history, led to approximately 739 heat-related deaths over a period of 5 days.[28] Eric Klinenberg has noted that in the United States, the loss of human life in hot spells in summer exceeds that caused by all other weather events combined, including lightning, rain, floods, hurricanes, and tornadoes.[29][30] Despite the dangers, Scott Sheridan, professor of geography at Kent State University, found that less than half of people 65 and older abide by heat-emergency recommendations such as drinking plenty of water. In his study of heat-wave behavior, focusing particularly on seniors in Philadelphia, Phoenix, Toronto, and Dayton, Ohio, he found that people over 65 "don't consider themselves seniors." One of his older respondents said: "Heat doesn't bother me much, but I worry about my neighbors."[31]
According to the Agency for Health care Research and Quality, about 6,200 Americans are hospitalized each summer due to excessive heat, and those at highest risk are poor, uninsured or elderly.[32] More than 70,000 Europeans died as a result of the 2003 European heat wave.[33] Also more than 2,000 people died in Karachi, Pakistan in June 2015 due to a severe heat wave with temperatures as high as 49 °C (120 °F).[34][35]
Our concern now is focusing on predicting the future likelihood of heat waves and their severity. In addition, because in most of the world most of those suffering the impacts of a heat wave will be inside a building, and this will modify the temperatures they are exposed to, there is the need to link climate models to building models. This means producing example time series of future weather.[36][37] Other work has shown that future mortality due to heat waves could be reduced if buildings were better designed to modify the internal climate, or if the occupants were better e
According to the Agency for Health care Research and Quality, about 6,200 Americans are hospitalized each summer due to excessive heat, and those at highest risk are poor, uninsured or elderly.[32] More than 70,000 Europeans died as a result of the 2003 European heat wave.[33] Also more than 2,000 people died in Karachi, Pakistan in June 2015 due to a severe heat wave with temperatures as high as 49 °C (120 °F).[34][35]
Our concern now is focusing on predicting the future likelihood of heat waves and their severity. In addition, because in most of the world most of those suffering the impacts of a heat wave will be inside a building, and this will modify the temperatures they are exposed to, there is the need to link climate models to building models. This means producing example time series of future weather.[36][37] Other work has shown that future mortality due to heat waves could be reduced if buildings were better designed to modify the internal climate, or if the occupants were better educated about the issues, so they can take action in time.[38][39]
The number of heat fatalities is likely highly underreported due to a lack of reports and misreports.[27] Part of the mortality observed during a heat wave, however, can be attributed to a so-called "harvesting effect", a term for a short-term forward mortality displacement. It has been observed that for some heat waves, there is a compensatory decrease in overall mortality during the subsequent weeks after a heat wave. Such compensatory reductions in mortality suggest that heat affects especially those so ill that they "would have died in the short term anyway".[40]
Another explanation for underreporting is the social at
Another explanation for underreporting is the social attenuation in most contexts of heat waves as a health risk. As shown by the deadly French heat wave in 2003, heat wave dangers result from the intricate association of natural and social factors.[41]
In addition to physical stress, excessive heat causes psychological stress, to a degree which affects performance, and is also associated with an increase in violent crime.[42] High temperatures are associated with increased conflict both at the interpersonal level and at the societal level. In every society, crime rates go up when temperatures go up, particularly violent crimes such as assault, murder, and rape. Furthermore, in politically unstable countries, high temperatures are an aggravating factor that lead toward civil wars.[43]
Additionally, high temperatures have a significant effect on income. A study of counties in the United States found that economic productivity of individual days declines by about 1.7% for each degree Celsius above 15 °
Additionally, high temperatures have a significant effect on income. A study of counties in the United States found that economic productivity of individual days declines by about 1.7% for each degree Celsius above 15 °C (59 °F).[44]
Abnormally hot temperatures can cause electricity demand to increase during the peak summertime hours of 4 to 7 p.m. when air conditioners are straining to overcome the heat. If a hot spell extends to three days or more, however, nighttime temperatures do not cool down, and the thermal mass in homes and buildings retains the heat from previous days. This heat build-up causes air conditioners to turn on earlier and to stay on later in the day. As a result, available electricity supplies are challenged during a higher, wider, peak electricity consumption period.[citation needed]
Heat waves often lead to electricity spikes due to increased air conditioning use, which can create power outages, exacerbating the problem. During the 2006 North American heat wave, thousands of homes and businesses went wi
Heat waves often lead to electricity spikes due to increased air conditioning use, which can create power outages, exacerbating the problem. During the 2006 North American heat wave, thousands of homes and businesses went without power, especially in California. In Los Angeles, electrical transformers failed, leaving thousands without power for as long as five days.[45] The 2009 South Eastern Australia Heat Wave caused the city of Melbourne, Australia to experience some major power disruptions which left over half a million people without power as the heat wave blew transformers and overloaded a power grid.
If a heat wave occurs during a drought, which dries out vegetation, it can contribute to bushfires and wildfires. During the disastrous heat wave that struck Europe in 2003, fires raged through Portugal, destroying over 3,010 square kilometres (1,160 sq mi) or 301,000 hectares (740,000 acres) of forest and 440 square kilometres (170 sq mi) or 44,000 hectares (110,000 acres) of agricultural land and causing an estimated €1 billion worth of damage.[46] High end farmlands have irrigation systems to back up crops with. Heat waves cause wildfires.