Mine runs pretty hot most of the time as well as I use it at about 75% brightness to have a nice bright screen and frequently use LTE. I keep it in a folio case 100% of the time which negates the heat issue but I do wonder if it is good for the internal components to run so warm without a way for the heat to disperse. Only time will tell. My guess is that if the battery deteriorates prematurely, it will happen for lots of users and Apple will end up replacing batteries without a fee. I bought Apple Care for the first time for an iPad with iPad 3 (I've owned all three generations) for this very reason, though.