a rug is the answer
The answer to this riddle is "a staircase". Of course the staircase does not actually move up and down, but when you refer to a staircase directionally, you are either going "up the stairs" or "down the stairs". Its function in and of itself is to "go" up and down.
a lift goes vertical. an escalator is moving stairs.
Temperature
It depends, do you fall down the stairs a lot? (if downward-forward) Do you run into walls consistently after going up? (if upward-forward)
chemical energy (stored in the muscles of the body) turns to kinetic energy (climbing up the stairs) and then is transformed to potential energy (once you reach the top of the stairs) due to your position.
A rug
the answer to this riddle is carpet
The answer to this riddle is "a staircase". Of course the staircase does not actually move up and down, but when you refer to a staircase directionally, you are either going "up the stairs" or "down the stairs". Its function in and of itself is to "go" up and down.
excolators handles
a lift goes vertical. an escalator is moving stairs.
Temperature
Stairs go up and come down as well.
The opposite of up the stairs is down the stairs, as the opposite of upstairs is downstairs.
The railing
Stairs, you go up you go down but the stairs never move.
the stairs
A cow can climb up stairs but not down.