Do you mean 90 C? Because I expect 90F ambient temperature whole summer and the phone has to be at least that much, even when shutdown. Add a little bit sun exposure and it can easily hit 120-130F without doing anything and I'm not talking Death Valley, Phoenix or Vegas, up there with outside temperatures hovering around 110 F or more, unless you don't come out from AC cooled room at all whole summer, the phone will be hot. If I remember correctly my computer CPU would start throttling somewhere around 80C, but my computer's GPU could go close to 100C. I would think phone is similar, except without active cooling, it probably starts to throttle sooner.
