Uses biomathematical modeling techniques and a computer to derive predictive formulas and other information about the incidence of altitude bends in humans with relation to prior denitrogenation, activity at altitude, and individual physiological characteristics. The models represent pertinent human functions, such as respiration and metabolism, and predict the effects of changes in these functions, as induced by alterations in total pressure, work level, and denitrogenation, on the formation and composition of bubbles in tissues. Bends is believed caused by the growth of gas bubbles in the blood and other tissues and their accumulation at specific locations, especially at the joints. The computer models are exposed to the range of conditions known to cause bends at altitude. Among other findings, model results strongly suggest that the rise in body-core temperature that accompanies exercise increases the incidence of bends at altitude. Thus, techniques that control core temperature near normal at altitude may be useful preventives.