Early nomadic shelters, including caves, animal skin tents, and igloos, were used for protection against wind, rain, snow, sunlight, and other forces of nature. These basic homes also provided defence against predators and were used to store a few important possessions. They were temporary, and proximity to a water source was of prime importance. For hunters and gatherers, shelter was an important aspect of survival. Health and comfort were not yet under consideration. As civilisation evolved, housing became more permanent, with increasing attention to well-being. The housing and utilities available in rich countries are vastly different from those in poorer settings. Unlike in industrialised countries where piped-in water, indoor toilets, and sewage systems are the norm, in the developing world these facilities are often not available. Waterborne enteric diseases, preventable by the supply of safe water, hand washing, and appropriate sanitation, continue to be a major disease burden in poor countries. Vector-borne diseases that can be controlled by screening and other barrier methods also remain an important health problem. Safe, comfortable, and healthy homes are an essential requisite for healthy living around the world, irrespective of culture or socio-economic status. Throughout the tropics there is a huge diversity in house design and use of building supplies based on centuries of indigenous experience, customs, and availability of local resources for construction. These differences in building style and materials affect the indoor conditions and comfort of occupants, which in turn influence the occupants' exposure to certain infectious diseases. In this book the authors describe the architectural designs and materials of rural houses in two countries in Asia (Thailand, Philippines) and two in Africa (The Gambia, Tanzania). They analyse the effect of design on the indoor climate and relate these factors to health, notably the risk of mosquito-borne infectious diseases such as malaria. Based on their findings and a detailed understanding of local building styles and preferences, they describe a series of house modifications that could enhance comfort whilst reducing health risks.