When you need to dial 9-1-1 on your mobile phone, it might be nice to have the phone direct as much power as possible to the cell transmitter, so you get a clear signal, no accidentally-dropped calls in the middle of reporting an emergency. Seems fairly obvious to me. But Apple filed for a patent on that:
Apple's iPhone Emergency-Mode Processor & Features Patent
I couldn't find a link directly into the USPTO, but you can use PAIR to search for application file number 11/999,547.