[Chronic exposure to cold is adaptation without stress ].

It has been established that prolonged continuous cold exposure (+4°C for 24 hours/day, four weeks) causes an increase in brown fat weight, hypertrophy of the adrenal gland, spleen and did not affect cortisol and corticosterone levels in the blood serum in rats. Gastric ulcers were not observed in the rats. Chronic intermittent exposure to cold (+4°C, 8 hours/day, 4 weeks) promoted an increase in the weight of brown fat, spleen, kidneys and heart, stomach ulcers and an alteration of cortisol and corticosterone levels were did observed. Short-term intermittent exposure to cold (+4°C, 1.5 hours/day, 4 weeks) did not affect the weight of brown fat, but promoted an increases in the weight of body, spleen, kidneys and heart, stomach ulcers were not found, cortisol and corticosterone levels was not changed.