Activation of the heat-shock response by whole-body hyperthermia or geldanamycin leads to an increased expression of the inducible Hsp72 protein in the mouse lung. Lungs from C57BL/6 mice were harvested 24 h in mice that underwent (A) a 20-min whole-body hyperthermia at 42° ± 0.2°C induced by exposure heating pad and warming lamp or were kept at room temperature and (B) a pretreatment with geldanamycin or its vehicle (1 μg/g body weight given intraperitoneally at 48 and 24 h before lung harvesting). One representative lung is shown for each experimental condition.