A limited number of experiments have shown that treatment of rheumatoid arthritis by means of cooling the entire body in cryogenic chamber reduces the pain in joints affected by inflammatory process and increases their mobility. The aim of the present thesis was to try explain the mechanisms responsible for the observed improvement of the patients' condition, and an investigation of the treatment's effect on selected hemodynamic indices. Tests were carried out on 63 patients with rheumatoid arthritis mainly in the 3rd and 4th stage of illness, all of whom had been treated for 14 days, once daily, by cooling the body for two-minute periods in cryogenic chamber with temperatures ranging from -110 degrees C to -160 degrees C, followed by kinesitherapy. It was demonstrated that after a single session in the cryogenic chamber, after 7 and 14 days the level of ACTH, cortisol and beta-endorphins in blood serum rises. The level of TSH, T4, T3, GH and 6-keto-PGF1 alpha+, however, remains unchanged. The cryogenic chamber treatment does not affect the heart rate, arterial blood pressure nor the value of the left ventricle fractional shortening index and its ejection, neither does it cause of arrhythmias and ischemic changes of the heart.