>>21922015
"The Gellar field was invented along with the warp drive, allowing warp-capable ships and their occupants to actually survive the hostile environment of the warp. It protects the ship and its occupants from the hostility of the warp itself as well as from the predation of warp entities such as Daemons. The Gellar field device emits a field called a Gellar field, essentially creating a bubble of real space around the ship. The weakening, failure, and collapse of a Gellar Field while the ship is traveling through the warp would be completely disastrous. Warp entities would tear the ship apart to reach and consume the souls of the crew."
This is from a Lexicanum article, referencing Codex: Chaos Daemons (4th Edition), p.43. I don't have the books here, so I can't check, but some kind anon may look it up and quote the rulebook itself.