A heat exchange apparatus (26) for condensing water from a flow of respiratory gas is disclosed. The apparatus (26) comprises a first portion having an inlet (28) and a second portion having an outlet (30), the inlet (28) and outlet (30) being connectable to a breathing system (10) and the first and second portions being arranged in flow series, wherein the first portion comprises a condenser (64) and the second portion comprises a heater (64) downstream of the condenser for increasing the temperature of the respiratory gas flow prior to the outlet (30).
