"The soup is hot!"
Translation:La supo estas varmega!
I don't think you can make it that clear. What is exactly the difference between warm and hot? Surely you can sometimes translate varma with hot. Many languages don't distinguish between warm and hot. Varmega is hotter than varma, but where you put the limit between the 2 words is up to you. When you speak about food I think varma would often be hot.