Health and performance of Antarctic winter-over personnel: a follow-up study.

The medical and service history records of enlisted Navy personnel who applied to the Operation Deep Freeze Program between 1963 and 1973 were examined to determine if incidence rates and performance criteria were significantly different between a group of winter-over personnel and a control group of enlisted personnel who were rated as acceptable by a screening team but who did not winter over. Results indicated that the overall incidence rate for the winter-over group was significantly lower than the rate for the control group. The winter-over group also had significantly fewer first hospitalizations for neoplasms, endocrine, nutritional and metabolic disorders, and diseases of the musculoskeletal system. No differences between the two groups were observed on any of the performance indices. Results suggest that wintering over in an extreme and isolated environment does not adversely affect subsequent health and performance of enlisted personnel.