Not warm up?

eg
If you run, warm up first.
After you run, cool down.
If you are just a spectator, don't warm up.

Phrasal verbs like "warm up" form negatives in exactly the same way as ordinary verbs.

I warm up. / I don't warm up.
He warms up. / He doesn't warm up.
I warmed up. / I didn't warm up.
etc.

Warm up! / Don't warm up! (imperative)

onizoWhat is the nagative form of "warm up?"?

Our cat is not friendly by nature. But if people come to the house, she will eventually warm up to them.
Our cat is not friendly by nature. Even if people come to the house, she won't warm up to them.

So sorry for you guys that I wasn't clear enough.

This warm up is for warming up food. You ask a baby that if he wants

onizoYou ask a baby that if he wants his food to be warmed up, and in short just ask "warm up?", but you don't get his response well, so ask the native form in short again by saying "1) Dont't warm up? Or 2) not warm up? Or 3) no warm up?"

"Don't warm up?" comes closest to being a proper sentence, but mostly this seems, in the context, like highly simplified ba

GPYhighly simplified baby talk. Is that the intention?

Thank you.

No. I want a simplified sentence, but not a baby talk, but more of regular simplified version. Does it mean that you would use all the subject and everything in this situation: you don't want it to be warmed up?

onizoYou ask a baby that if he wants his food to be warmed up

Babies learn "hot" and "too hot" early in life, but not the concept of "warm up." That's pretty advanced.
The simplest way in baby terms is to ask for a yes/no:

Too hot?
Too cold?

This is the closest I can get to what you are trying:

Do you want it warmed up? Not warmed up?
Do you want me to warm it up? Not warm it up?
Do you want me to warm it up? No?

But, as AS says, "warm up" is more advanced than basic words like "hot" and "cold".