Putting privacy mirror film on double glazing

[CoralBells]

I read that if you put mirror film on certain types of double glazing that contain a gas (?) it can overheat and crack. Is that right. I think mine is just old upvc double glazing, so would it be OK? I assume it's just air in between the panes?

I've had film up for 2 years and no issues, never even considered there might be!

Thank you. Is yours mirrored and did you put it on yourself? I've got the frosted one which I put up myself and is fine.

I have it on several of our UPVC windows. It's the mirrored film stuff which I bought on Amazon. Never knew there might be an issue with it!

It's probably been there about 6-7 years (if not longer) and we've had no probs so far!

Thanks. Think I'll go for it