Is this hot as in temperature or hot as in spice?
Both, as in English.
E.g. weather, food (where both apply - steaming garam, garam masala ('hot mix [of ground spices]')), and 'potential mates' can be garam.
The food is warm. This was not accepted. Why? Is there a different word in Hindi for warm?
It should be accepted.
Why is "it is hot food" wrong? Would there be a different word order?
I think that would be यह गरम खाना है.