Kuhnen, G. 1997. Reduction of fever by housing in small cages. Laboratory Animals 32, 42-45.

At the beginning of the experiments individual hamsters housed in small standard cages had higher temperatures compared with hamsters housed in larger cages. This was taken as an indication of a higher stress level in the small caging environment. Hamsters housed in large, barren cages had higher temperatures than hamsters housed in large, environmentally enriched [with running wheel, climbing trestle, tube, etc.] cages, suggesting a higher stress level in the large but barren cage environment. Housing [individual hamsters] in small cages diminished the fever response [to injection of lipopolysaccharide from Salmonella typhosa] significantly by approximately 20%, and is likely to be due to a higher stress level. The findings demonstrate that the results of physiological experiments are not only influenced by the experimental design, but also by pre-experimental housing conditions.