I don't think you could actually burn it while keeping a watch on it....severely dry it out, maybe, but burn, no. Anything up to 275 should be a relatively safe range to cook it at just to speed it along...patience does do wonders though. You're now suffering through the "plateau" stage where the fat is rendering out, turning to liquid, and thus cooling the meat, so your temp is going to stall for a while. The slower you can run through the plateau, the more tender the meat will be. (I think that's how this all goes...somebody will correct me if I'm wrong).