system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do hospitals evacuate everyone in the event of a fire?

Hospitals often have patients who are bed-bound, wheelchair-bound, comatose, or even in surgery. When the fire alarm goes off, how do staff evacuate all patients quickly?
gpt
Hospitals are designed so that in the event of a fire, doors will close and will prevent the fire from spreading until firefighters can deal with it. The doors are rated, usually by number of hours, for how long they will hold back a fire on the other side.