What's a Hot Mic in Warzone?

As used in online gaming, it refers to when a player's microphone is heard being constantly on, and is also used as a call-out Hot mic! for everyone to check microphone settings. ...

What does the expression hot mic mean?

a microphone that is left on accidentally so that people hear something someone says that is private or embarrassing.

How do I fix hot Micing?

Set your default windows mic to stereo mix or anything else, then force TeamSpeak or whatever you are talking on to the correct input. Then in game voice record to 0. This way seems to work 100% of the time. When this happens, you can just tap the mic key again to fix it, you don't have to go into settings.