Clinical observations on tropical men during their sojourn over the Arctic region.

: In the present study, besides a detailed clinical evaluation, roentgenographic changes in cardio-respiratory system in Indian soldiers (IS) during their 60 days stay at the arctic have been observed. These results have been compared with the responses at Delhi (before cold acclimatisation) and on return to Delhi (deacclimatisation). An attempt has also been made to compare the same physiological variables with those of Russian Migrants (RM) and Russian Natives (RN) in the arctic region to review significant differences if any. Heart Rate (HR) did not show much change; there was a tendency to increase in both systolic and diastolic blood pressure; and Kerdo's index inclined towards increased sympathetic activity in IS. X-ray chest (PA View) did not show any appreciable change in the lungs in the three groups. One subject amongst IS showed cardiac enlargement and RN subjects showed prominence of pulmonary artery and pulmonary vascular markings. All these physiological changes aim at increasing the cardiac output to overcome the ill effects of cold. Pneumopathy, a clinical condition of increased pulmonary haemodynamics could have resulted in the prominence of pulmonary artery and pulmonary blood flow in the RN. Most of the physiological changes reverted to the baseline value on return to Delhi thus proving that there were no permanent changes during short stay at extreme cold conditions.