A sleeping porch is a porch, often a second story porch or back porch, that is screened in and furnished for sleeping and/or advanced relaxing on hot summer afternoons, evenings and/or nights. The screening was a critical feature, as it allowed cooling breezes in, but kept mosquitoes and other bugs out.
Because a sleeping porch is a more private area than a regular porch, they may be more closed in, with low half-walls rather than railings, and with framed windows with some sort of curtains or shades. In those few newer homes that feature a sleeping porch, the room may more closely resemble a sunroom or conservatory, being fully enclosed and fitted with glass windows, and often built in the shape and size of a regular room, rather than the traditional elongated form a of porch.
Sun porches became popular in the American South in the early 1900s, both as a way of managing the heat of summer and as a presumed health treatment. Fresh air was believed to benefit people suffering from respiratory problems and general ill health, including tuberculosis, the leading cause of death at that time. Their popularity was based on the decline of the miasma theory of disease and the related fear of night air in the 1860s and 1870s, and the 1908 discovery that malaria was carried by mosquitoes. They quickly started to fall back into disuse as air conditioning became wide-spread in the 1950s.