Homeless shelters are a type of homeless service agency which provide temporary residence for homeless individuals and families. Shelters exist to provide residents with safety and protection from exposure to the weather while simultaneously reducing the environmental impact on the community. They are similar to, but distinguishable from, various types of emergency shelters, which are typically operated for specific circumstances and populations—fleeing natural disasters or abusive social circumstances. Extreme weather conditions create problems similar to disaster management scenarios, and are handled with warming centers, which typically operate for short durations during adverse weather.
Hundreds of homeless individuals die each year from diseases, untreated medical conditions, lack of nutrition, starvation, and exposure to extreme cold or hot weather. In a mild-wintered San Francisco in 1998, homeless people were purportedly 58% more likely to perish than the general population. In New Orleans, approximately 10,000 homeless were unaccounted for after Hurricane Katrina in 2005. Residents of homeless shelters may also be exposed to bed bugs which have been growing more prevalent in countries such as the United States, Canada and in Europe. Some residents of shelters have reported sleeping in roach-infested spaces at various shelters.
Researchers have found that homeless people are at high risk for respiratory tract diseases, such as tuberculosis, peripheral vascular disease, dermatology problems, and infectious diseases, including sexually transmitted diseases. These high rates are attributed to environmental pollution and other risks associated with street life, including trauma, poor nutrition, a lack of access to personal hygiene facilities, and crowding and debilitation, which increase the risk of infectious disease. Besides physical health problems, homeless people are also at great risk of mental health issues resulting from alcohol and drug abuse as a lack of societal concern and care.