Translation:Korea is hot.
I don't know if anyone else does this, but dont get confused with 한국 and 학교. And the word ~이 talks directly about Korea. So if you want to just talk about Korea, use ~이 instead of ~은. And 덥습니다 talks about the feeling of you, someone, or something. While, 뜨겁습니다 tslks about an object being hot (hot to the touch).