This one was a pain for me, maybe change mode. One trick that seems to work is to watch someone go to a heat source and then throw the ammo crate on them. Avoid heat areas where there is already a crate.
The one I'm struggling with is Adrenaline Injector kills in freeze zones. I assume freeze zones are everywhere that isn't a heat zone, maybe? Anyway, whenever I use the injector I can barely see at all. Inside is like completely black.
Really wish the would either make the challenges written better, or make them work better.
