Actually the Vikes got scolded earlier this year for heating balls. It was a cold game. But in general once the balls have been approved you’re not supposed to mess with them.
Seattle’s hands aren’t totally clean as Cowboys’ fans can recall
Seattle K ball conspiracy theory still lingers
http://espn.go.com/blog/dallas/cowboys/post/_/id/4697590/the-curious-case-of-the-k-ball-vs-seattle
There must be some regulations that I don’t see in the rule books that I looked at online.