How can I reduce heat on sony lcd kdl-37l4000

If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Line faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.
Search the site by type in the "brand name" to your device; (Exclude the model number), in the "Search box at the top right of the display window of the Homepage" to get gathered related posts

To make it a hard reset, just unplug the TV from AC mains wall socket, and re-plug it back after 15 minutes or so. This procedure will make it a hard reset. If you want to make it a system reset [Factory Reset]; you have to enter its service mode option, and select the factory reset option. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Service mode entry, adjust and exit procedure to many popular brand TVs are given. Never forget to exit the service mode, after all adjustments have been done.

If only when playing a dvd it is not likely to be a problem with the TV set--have you checked to see if issue when played at another set?

try to check first the voltage requirements at the back of your tv it is printed there, but most of the tv models specially the lcd it is auto volts.

Sony Bravias have bad power supplies. I would contact sony customer service

hit the display button on remote should turn it off

Just mute the TV and you will get sound out of your headphones. You may have to turn the TV sound up though.

I think that Sony Bravia are sold with dual voltage, 110V and 220V. All 220V devices work also on British 240V network.

If an electronic device is not compatible with the 240V/220V network, then the PSU must be replaced.

In your case the unit should be dual voltage, compatible with 220/240V networks. Just ensure checking the user manual, or the tag at the back of TV.
All you need in that case is an adapter that can be purchased at any local electrical shop (eg. Curry's if you are in UK).

Regards.

Sounds like you cant have set up the scart cables properly. Im unimpressed with BT for not setting it up for you, why didn't they?
Plus you will not need the freeview box if you have BT Vision, so i would take out the freeview box and just connect one end of the Scart lead into the back of the BT Vison box then put the other side of the lead to the Back of the TVs scart socket. Then all you need to do now if change the channel to AV1 OR AV2 or whatever channel you have.

It is not designed to be changed over. Even if it was, it would probably cost more to do it than what it would be worth.