That's a bad place for a laptop, assuming your bed doesn't have a hard surface like a table or a desk. If to be used on the bad you need to place it on a laptop cooler to have good ventilation.
It's quite well possible there is heat damage, and some components need to be replaced. To test that, burn a Linux disc (Ubuntu, Mint) or make a bootable DVD from it and boot from that to see if it's OK then.
I have an ASUS U46SV (Core i5, 8GB DDR3, 750GB, NVIDEA GT 540M 2GB, 14") which was working fine. It had been running for about 2 days straight and so I put it in hibernation. Came back home, lifted it off the table, put it on the bed, switched it on and all I saw was a white screen right from the moment the power button was pressed.
Following this I have taken the following steps:
a. External Monitor: Connected to two different monitors, CRT and LCD via VGA Cable. Working fine on both of them.
b. BIOS: Opening BIOS sometimes results in the BIOS opening properly while sometimes the entire interface seems stuck. All options such as Main, Boot, etc get displayed only when I scroll to them. (BIOS is the latest version and when I tried to still update it using ASUS Easy Flash utility within the BIOS itself, it says "Build version is too old" or something to that effect!)
c. The system is working fine. In fact, typing this on the same system.
d. There was no physical damage such as dropping, jerk, etc.
e. When connected to the CRT monitor (4:3 aspect ratio), the resolution difference between it and the laptop display (16:9 or 16:10, i don't exactly remember) resulted in a slight shaded region. That is, instead of the entire display being white, only a block of ration 4:3 was white with rest as slightly shaded grey.
I sure hope its not a faulty display coz that costs over Rs. 10,000 for this mode! Can anyone help me out with this?