20 Things You Didn't Know About Heat

20. The Bank Robbery Gunfire Was All Recorded Live On-Set

It's no secret that Michael Mann has a penchant for gritty authenticity where his action sequences are concerned, but even so, he went to extreme measures to ensure Heat's iconic bank robbery shootout sequence not only looked real, but sounded it too.

While it's common practise for movie gunfire to be dubbed during post-production, Mann wanted the movie's shootout to sound totally unique in its "realism," and so had microphones placed around the shooting location, allowing him to capture the audio live.

As a result the gunfire doesn't sound as cleanly post-produced as it does in most Hollywood action flicks, ensuring the audience really feels like they're down in the weeds with these characters when it all kicks off.