The physiology of pressure suits.

D E S P I T E the recent advances in the field of pressure suit development no suit exists which, while giving adequate protection against the effects of exposure to low barometric pressure, does not seriously interfere with the functional efficiency of the wearer. Thus in high altitude military aircraft the cabin is generally pressu,rized, and pressure suits, if worn at all, are used for emergency purposes o n l y . I t is poss ine to envisage two different sets of conditions under which a pressure suit may be employed in the event of failure of the pressure cabin. The suit may be employed to give short term protection to the wearer, in order that he may descend to an altitude where protection is not required, either in his aircraft or following escape from it. Alternatively, the suit may be used to give protection for a long period to enable the airman to remain within his aircraft at a high altitude when the pressure cabin has failed. The two physiologic effects of reduced pressure, which are of vital importance to this report, are anoxia and decompression sickness. Experience has shown that freedom from serious anoxia may be obtained in pressure suits by the breathing of pure oxygen