Jumpsuits are uniforms that pilots and spaceship crewmen wear. They have the ability to safely seal the body and maintaining life support, in case of vacuum conditions, such as depressurisation or ejection. Although crewmen wear jumpsuits during service, usually they don't wear the accompanying helmet and gloves, except when there is a danger of breach (eg. an attack).
The wrists (and possibly the legs) have pressurized cuffs, sealing the suit shut. Hands are exposed, but there are gloves; those have special locks that, once closed, the pressurized cuffs release, supplying air pressure to the hand and fingers.[1]
- ↑ William R. Forstchen, Action Stations, Chapter 3