I have been using my 372 box now for a few months since my Humax packed in.
I have it on for more than 10 hours a day and have no problem with heat.
This is because it has been moddified with a heatsink mod and an internal fan to keep it cool.
This has been well covered in the Glitchy box thread and it works.
I get no failed recordings, my box never slows down or freezes and it is cold to touch after over 10 hours use.
These mods have proved to work but the standard Huawei boxes are all prone to problems with the heat they produce.
My box is only plugged in when I want to watch TV,the rest of the time it is left unplugged.
If there is a software update it will automaticly check when you switch on so when someone says it needs to be left on standby all the time they are wrong.Leaving the box on standby builds up the heat inside the box and over heats the CPU.
John