Extreme Temperatures (Heat and Cold)
Extreme temperatures can cause illness, injuries, and deaths as well as damage to infrastructure such as roads, bridges, dams, etc. Agriculture and fisheries are specifically dependent on certain climate conditions. Excess heat events can impact crops, livestock, fisheries, and shellfish, and thereby reduce vital food supplies and increase prices. Electrical transmission systems may be affected by sagging power lines which may short out because of high temperatures. The unusual demand for excess energy may lead to blackouts and blackouts may lead to increased crime, particularly in large cities. Increased air pollution may be associated with the high temperatures and the heat island effect of urban areas. (See Chapter 2, “Air Quality (Outdoor [Ambient] and Indoor).”) Transportation may be impacted because of the frequency and intensity of extreme weather events. Higher temperatures can cause roadways to soften and expand, especially in high traffic areas, and place extra stress on bridge joints. Railroad tracks may expand and buckle. Airlines may face cargo restrictions and flight delays. The demand for water increases sharply and may result in shortages in various areas.
Extreme heat causes more deaths each year than the combined mortality due to hurricanes, lightning, tornadoes, floods, and earthquakes. In 1995, there were 465 heat-related deaths in Chicago. From 1999 to 2010, there were 7415 heat-related deaths in the United States. (See endnote 16.) The number of heat-related deaths is rising because the number of heat-related events is increasing.
Some people are more vulnerable to heat than other people. Vulnerability can increase because of the degree of exposure, length of exposure, and the individual sensitivity to heat. Vulnerability can increase because of the individual’s socioeconomic status, degree of overcrowding in the structure and community, accessibility to air-conditioned facilities, and level of literacy in the English language. Isolation especially among the elderly can lead to serious problems related to excess heat especially because of restricted physical capabilities, a lack of communications with others, and a lack of an understanding of what is occurring and how to rectify the problem.
Heat stress is of greatest concern for the very young, the elderly, the overweight, the chronically ill, individuals on certain types of medications, and individuals who are working in the extremely hot environment. The young child or baby is very sensitive to high temperatures and can quickly get stressed although not showing immediate symptoms. They dehydrate very rapidly. The elderly are at increased risk because the body may be unable to cope with heat as a younger person could and cannot cool itself normally. Additionally, the individual may have: reduced mobility; confusion or mental problems; chronic medical problems that require medication that can affect the ability of the body to maintain a proper fluid level such as diuretics; pharmaceuticals that limit or reduce the amount of perspiration and therefore deprive the body of a natural cooling mechanism; pharmaceuticals that can increase the risk of sunburn when exposed to the sun for limited periods of time; and kidney conditions which can be affected by the amount of fluid intake. In addition, there may be environmental problems because of the lack of air circulation and/or air-conditioning during times of high heat levels. Severely overweight individuals not only have a greater potential for a variety of diseases including heart disease, high blood pressure, cancer, renal disease, diabetes, etc. but also may have profuse sweating and fatigue leading to heat emergencies. The chronically ill have already been weakened by their conditions and are typically not very mobile or even immobile and therefore are at much greater risk of serious problems caused by sustained heat events. They may also be seriously dehydrated. People in an urban setting without green areas may be more susceptible to heat than others. (See endnote 17.)
Individuals working in very hot environments are exposed to all forms of heat illnesses. This is especially true of young people starting on new jobs in the hot summer outside or in very hot areas of businesses or factories. Normally, they have not had enough time to be acclimated to the higher temperatures in their surroundings.