It happened to one of mine yesterday for the first time in a while. The temperature went up to 40 degrees C before returning to low 30's now. My other machine was OK.
To get this info key in 2846 whilst in the Technical Information / Technical Help menu.
It would seem that the fan also switches off tus the temperature goes up. Power down and up and wait for the light to be red worked to return to normal. No recordings were lost but one failed. This was a weekly recording which was an hour out last Monday following the clock changing, so was this somehow a consequence of the clocks changing?