I'm not sure what your point is. The hottest it's been, ambient-wise, in this room has been about 83F, and that was when we had a hot spell in Seattle. We don't do air conditioning here, for the most part, so it was ridiculously hot. I used my iMac all day and night over that time-period, and never had any IR.
Am I saying it's not possible for IPS panels to have IR? No! I'm saying MY panels do not have any IR! Surely that's all that matters, right? IF my panel starts to display even a HINT of IR, I'll be sure to update that here. But I've never owned a panel with IR.
My iPhones have always stayed in my pocket, with the screen facing toward my leg. What do you think the temperature of that display is? ? (I've owned every single iPhone, which means three of them are IPS panels, the 4, 4S, and 5). And have I seen IR on my iPhones? No! Not a hint of IR, there.
Just because my car is able to do 0-60 in 4.6 seconds doesn't mean I'll achieve 0-60 in 4.6 seconds, no matter how hard I try.
See what I'm saying?
I'm not sure what else you want me to say, really. My panel has ZERO IR. Lots of people's panels have ZERO IR. My menu bar is up probably 16 hours of the day. I've used IPS panels in hot temperatures. I can display that grid pattern for 16 hours straight if you like, and still won't see any IR. Are there some conditions out there that MAY cause me to see IR? Maybe! But I haven't found them. Good grief, get over it, - mate.