In vivo study. (a) Temperature for the Hygroster, Hygrobac, passive Performer and active Performer with the Provider set at T1 (40°C), active Performer with the provider set at T2 (50°C), active Performer with the Provider set at T2 after 12 hours of use, and active performer with the Provider set at T3 (60°C). (b) Absolute humidity (AH) for the Hygroster, Hygrobac, passive Performer, active Performer with the Provider set at T1, active Performer with the Provider set at T2, active Performer with the Provider set at T2 after 12 hours of use, and active performer with the Provider set at T3. Data are presented as means ± standard deviation. +P < 0.05 versus Hygroster; *P < 0.05 versus Hygroster, Hygrobac and passive Performer; °P < 0.05 versus active Performer set at T1.