The superstition that night air is noxious seems to have originated in ancient Rome where infectious breezes from surrounding marshes were said to cause malaria. Not until 1898 did scientists associate malaria with largely nocturnal mosquitoes who live in swamps and marshes and who pass the disease by introducing a parasite into the blood of its human host. Proper drainage helped to eliminate the problem in a number of areas. However, the superstition about night air lingered among the older and less educated who commonly insisted on sleeping with closed windows, even during the heat of summer.