Abstract: An adjustable bed system includes a frame structure, a back lifting assembly and a leg lifting assembly pivotally connected to the frame structure, platforms having a plurality of openings, disposed on the frame structure and operably coupled with the back and leg lifting assemblies, a mattress having a plurality of through holes and disposed on the platforms so that the plurality of through holes is aligned with the plurality of openings, respectively, and a plurality of fans installed in the plurality of openings of the platforms such that each fan is in communication with a respective through hole of the mattress for operably moving air via said through hole into the mattress body and outputting the air from the top surface of the mattress. Positions of upper and lower portions of the mattress are adjustable based on operations of the back and assemblies.