A solid-state lamp comprises a body having a first chamber with inlet apertures and a second chamber with outlet apertures. The chambers are interconnected in fluid communication by one or more passages. The lamp further comprises a thermally conductive substrate having a heat radiating surface located within at least one chamber and one or more solid-state light emitters, typically LEDs, mounted in thermal communication with the thermally conductive substrate. The lamp is configured such that in operation heat generated by the LEDs is radiated by the substrate into one or both chambers causing a difference in air pressure between the chambers that results in surrounding air being drawn into the inlet apertures, flowing through the chambers via the interconnecting passages in the substrate and exiting through the outlet apertures thereby cooling the substrate and LEDs.