is it a TV with fans blowing inside ? if so then your tv might be working as a vacuum cleaner !
best practice if it is not under warranty anymore is to unscrew all screws and clean out all dust from inside.
It might be that the motherboard is allready affected by the heat and some connections or components are busted ...
there is a way to repair this but at your own risk !
I tried this a few times with graphic cards and it worked for 90%
I tried it for a 3 TV's and only once it worked...
So I cannot guarantee much good for it !
unless there is something else going on, like bad network connection ?