Abstract: An assembly for use as a sun bathing spa and as a sauna, which is constructed of light weight materials, so as to be highly portable for use in a yard outside of and near to a residence or otherwise and which includes an air conditioning system for comfort of a person lying prone within a frame of the assembly. A heat transfer unit, which may be an air heater or dehumidifying coil, is disposed in a first end member of the assembly for providing warm or cooling air as the case may be, which can be directed by blowers through air passageways in side members of the assembly to be directed across the body of the person lying within a frame of the assembly to comfort the person in both low temperature and high temperature ambient environments. Transparent and foam covers can be used over the assembly to convert the latter from a sun bathing spa to a sauna.