Abstract: An infant incubator. A substantially rectangular patient support tray forms the floor of an occupant compartment. A substantially rectangular plate is disposed beneath the tray to define therewith a return flow path for taking atmosphere from the compartment from opposite longitudinal edges of the compartment floor. A base is provided beneath the plate to define therewith a delivery path for supplying atmosphere to the compartment at opposite transverse edges of the compartment floor. The base includes a heater to heat the atmosphere flowing over the base under the action of a centrally located impeller indirectly coupled to a motor located beneath the base. Humidifying means can also be provided.