Why are you studying in warm/hot? Come out and study.

Hi teachers,

Let’s suppose there’s a power cut and a student is studying in his room where there is no fan on. Is the following sentence correct to ask him?
Why are you studying in warm/hot? Come out and study.

Many thanks.

Why are you studying in that heat? Come out here to study.

Thank you, Madam BN.

What is the problem with the red part?

‘warm’ and ‘hot’ are the wrong structures.
It should be
in that warmth
or
in that heat.