What other apps burn as much iphone battery life? Would be interested to compare. Previous waze versions on previous iphone versions (4S) did not do this on the same route. Seems possible that Waze doesn't get along with iphone 5 hardware or software.

Waze or any other app which is constantly using GPS and cellular data and bluetooth will increase device temperature. Even more so when in the sun or in a warm vehicle. This is always more problematic during summer months. But it's not necessarily specific to Waze. It is recommended to either keep your phone out of the sun or put it in a vent-mount which can blow air over the phone.

I just had the same experience today. Phone was burning to the touch. Disappointing. Does the tomtom app overheat?