The Nintendo Switch is a great system, but it appears to be subject to an odd variety of small-scale issues. The weird thing is nothing that has come up has been widespread, and things like the dock causing scratching or the infamous Joy-Con signal problems were surprising to Nintendo. Now a new problem has appeared, although only a few people seem to be experiencing it. A NeoGAF user reported that his Switch, primarily used in TV Mode in the dock, overheated to the point of the tablet unit actually warping. Sure enough, the user provided photographic evidence and there is a definite curve to their Switch now. Yikes.
Many other forum users seemed shocked, as they had used the Switch in TV mode just as much. One person even went as far as to say their home has heating issues, and they still haven’t had the same problem.
So far, it seems like the Switch warping is a difficult problem to replicate. This indicates these are faulty units, rather than universal manufacturing problems. Hopefully, this person can get their unit swapped by Nintendo. In the meantime, maybe check yours for any unusual characteristics.
Source: NeoGAF