The term 'It's Full of Hot Air' can be solved by the crossword solutions FLUE, SAUNA, and DRYER. FLUE is a duct or chimney that carries off smoke or gas from a fire or furnace. A SAUNA is a small room or house designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these rooms. A dryer is an appliance used to remove moisture from clothes, towels, and other fabrics. All three of these solutions are related to hot air, as they all involve the use of heated air in some way.