Be in/get into hot water
Definition 1 of 1
Pro Tip 1/3Figurative meaning
The phrase doesn't involve actual water. It's a metaphor for trouble or criticism. 
After losing the company money, Jim was really in hot water with his boss.
Pro Tip 2/3Severity varies
The phrase can refer to trivial trouble or serious repercussions, depending on context. 
I was in hot water for being ten minutes late, but it was nothing a sincere apology couldn't fix.
Pro Tip 3/3Not always literal
Sometimes it's used humorously or sarcastically, not to denote real trouble. 
He's in hot water now for eating the last cookie, but we're all just teasing him.