He didn't realize how pleasantly warm it was outside.
The lady seemed to enjoy these days, the ones where the sun was out most of the time. It seemed like even an old robot like him could appreciate this particular day, and he found himself basking near to the apple tree.
It was practically worth overheating if he was able to lay outside in this sort of weather and thoroughly enjoy it.
Not a lot of pondering on Chell's end was spent on wondering how he'd fallen asleep. Most of the pondering was spent on how the hell she was going to lug him back.