Abstract: A humidity moisture exchanger (HME) for trapping heat and/or moisture normally lost during mechanical ventilation and the like. This HME includes a housing having a first chamber and a second chamber. The second chamber includes a pair of fluid ports connectable, in series, to a fluid flow tube extending from the patient. Inside the housing is a filter or an absorbent heat and moisture collecting material. To permit the uninhibited passage of fluid through the housing, the absorbent material is removed from the second chamber area and temporarily stored within the first chamber area.