Vacuum

A vacuum is an area that is virtually empty of matter, usually found in space. Most life forms cannot survive in a vacuum for very long.

The few exceptions include

 * Time Lords, for limited periods (DW: Four to Doomsday),
 * Daleks (DW: The Parting of the Ways),
 * Cybermen (DW: The Moonbase),
 * Toby Zed while possessed by the Beast. (DW: The Impossible Planet)

People known to be killed by exposure to vacuum include

 * Katarina, (DW: The Daleks' Master Plan),
 * Kirksen (DW: The Daleks' Master Plan),
 * Scooti Manista (DW: The Impossible Planet)
 * Lynda Moss. (DW: The Parting of the Ways)