You're getting close to the Yeast Death, but you're not quite there yet. That's pretty hot but the yeasties should survive. Muntons yeast is dry correct? Did you rehydrate it or did you pitch it straight? If you pitched it straight it might take some time for any activity to start. Just let it go for now and see if you get any activity. If nothing happens after 3 days or so, I'd repitch. If it does start to ferment, then you're in business, though you might get some different flavors because of the temp. I'm not too sure about this but you might want to condition the beer a bit longer to mellow out any off flavors...