It doesn't sound natural without 'too".

"This coffee is too hot to drink".It emphasizes that you can't drink it 'cause it's hot. Otherwise you can use similar phrases "This coffee is still too hot.I can't drink it" etc.

Can it be without 'too'?* "Can it" is often used for questions. "It can" for making statements. See if you can identify the difference in meaning between the below sentences. I explain afterwards: 1. "Careful, the coffee is hot." or "this coffee is hot" (omitting "to drink"). 이 커피는 뜨거워요. 2. "This coffee is too hot to drink." 이 커피는 너무 뜨거워서 먹기 힘들어요. 3. "This coffee is still too hot." 이 커피는 아직 뜨거워요. 1. focus is on the temperature. 2. focus is on the ability (or inability) to drink. 3. focus is on the time (nothing has changed).