THE "HEAT ISLAND" effect of large urban areas increases the
risk of heat-related illnesses in city dwellers. Meteorologic
conditions that increase exposure and inhibit heat dissipation include
prolonged periods of ambient temperatures at or above body temperature,
high humidity, increased barometric pressure, and reduced wind.
Perhaps the most important socioeconomic risk factor is lack of
access to air-conditioning. Electric fans do not significantly reduce
risk because convection requires that moving air currents be cooler
than body temperature. People living in apartment buildings, in upper
floors, or in flat-roofed buildings are at increased risk. Air
conditioners may not be activated because of concern about utility
bills. Fear of crime causes people to keep windows and doors locked or
to resist leaving their homes to visit cooling centers. Social
isolation is also a risk factor.
Blum LN, Bresolin LB, Williams MA, for the Council on Scientific Affairs . Heat-Related Illness During Extreme Weather Emergencies. JAMA. 1998;279(19):1514. doi:10.1001/jama.279.19.1514