Blanket

These commands change your position. When you REST or SLEEP, you
regenerate hit points, mana points, and movement points faster.
However, you are more vulnerable to attack, and if you SLEEP,
you won’t hear many things happen. Sleeping on bedrolls, inside
tents, and on beds in inns greatly increases the rate of healing.

Use STAND or WAKE to come back to a standing position. You can
also WAKE other sleeping characters.