2. An apparatus in which environmental conditions can be set and controlled: The biologist used an incubator in the lab for observing the growth of rare species of orchids.
3. An enclosed system in which prematurely born infants are kept in controlled conditions, as with proper temperature, for protection and care: Incubators are used in microbiology for culturing or growing bacteria and other microorganisms.
Incubators in tissue culture rooms are used for culturing stem cells, lymphocytes, skin fibroblasts and other types of cells.
In a hospital nursery and newborn intensive care unit (NICU), incubators serve to house and maintain premature and ill infants.