I'm a 47 year old female and have been running since I was 8. Recently, my Dr. told me to run with an epi-pen because I get hives sometimes after my run. She said I basically am allergic to exercise and should not even run or don't run alone! (can you believe that; after all these years) She said I could have a bad reaction. I carry my phone with me more for the music, but I also keep Benadryl in the case and only carry the epi-pen in the winter when I wear a jacket. I like the idea of the 911 app.