Varying temperatures (35.5 degrees C, 38.5 degrees C, 41 degrees C) only minimally affected growth rates in vitro of Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa, as well as bactericidal rates and postantibiotic effects of several antibiotics. However, MICs were reduced at least four-fold by increasing temperature in 25% of the drug-organism combinations tested.