Answer:
The figure of speech in "it is burning" is a hyperbole.
You can reword that sentence as "it is extremely hot outside."
Step-by-step explanation:
A hyperbole is a figure of speech that uses exaggeration to express a feeling or an idea. For example, when you tell someone you have called them a million times, you are using a hyperbole. You haven't actually called them that many times, you just want them to know that you called a lot.
It is quite common for people to use hyperbole when talking of the weather. We say it is burning hot when we mean it is really hot; we say it is freezing cold when we mean it is very cold. It is not really burning or freezing, we just exaggerate it to make our point.
A way to reword "it is burning" is by removing the hyperbole: "It is extremely hot outside."