Pressure suit

A pressure suit could be worn to survive for a short time in the Time Vortex.

The Eighth Doctor, Liv Chenka and Helen Sinclair found three aboard a Gallifreyan escape shuttle and wore them when escaping from the Vortex. (AUDIO: Ship in a Bottle)

The crew of Fireball XL5 donned pressure suits while they explored the Batman-occupied asteroid in hyperspace, knowing that a long search in zero atmosphere conditions could have awaited them. (COMIC: The Batmen)