After an initial acclimation period at standard temperatures, mice were randomly placed in static cages (3-5 mice/cage) in specialized climate chambers (Powerscientific, Pipersville, PA). Chamber temperatures were set to either 22°C or 30°C with relative humidity set to 30%. After 7 days, groups of mice (n=10/group) were euthanized without further manipulations to establish the effects of ambient temperature on select markers of inflammation including cell counts and cytokine concentrations in plasma and peritoneal lavage fluid. Spleen cells were harvested for total counts and in vitro stimulation. Additional groups of mice exposed to either 22°C or 30°C underwent cecal ligation and puncture surgery to induce polymicrobial peritonitis, then returned to their assigned housing temperature. Survival was monitored for 7 days after surgery. In a separate cohort of mice, inflammatory responses at 6 hours after surgery were examined in the systemic (blood) and local (peritoneal lavage) compartments. the experiment was repeated with mice implanted with a thermistor to monitor body temperature over 72 hours.
