Do substances have to be cold to freeze?

No.

Explanation:

90% of the time when someone hears the word "freeze", they think cold.

However, at its core, to freeze, is to become solid, and there are many solid materials that aren't necessarily cold, for instance Lava is hot, and once it cools it becomes a form of rock that is not necessarily cold, however it has frozen into a solidified form.

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of carbon is as shown here in the image.