Compact bone changes in cold-exposed rats.

Rats exposed to cold stress show a reduction of relative cortical thickness in their long bones. The reaction resembles reduction of cortical thickness observed in Asiatic humans of the Mongoloid race, in whom many morphological features have been postulated to be cold-adaptive. However, until it can be established that the physiological processes underlying the experimental and phylogenetic condition are similar, no extrapolation can be attempted from the one to the other.