....but might be a problem if the phone went kaput far from home all of a sudden because of it someday.
I keep an old phone with me nearly at all times, just for that reason. I'm really rough on phones (I don't believe in cases) but I do travel a lot, and the hassle of going without a phone - especially if you're away from home - shouldn't be something you worry about.
Find, or buy an older phone on ebay/craigslist, and put it in your glove box, back-pack, tool-bag, suit-case, or whatever you typically have with you. Just make sure they share the same charger. If anything happens to your 'main' phone, just pull out the backup, call the activation number, and you're back in business...
AND - make sure that you have your phone setup to backup your contacts & other important info to the cloud.
I say that as a guy who lost 2 year's worth of phone numbers last summer, when my phone got wet, and I didn't have my numbers backed up to the cloud, but rather only stored on the device.
I personally use androids, so my short-term replacement was $45 on ebay, and now serves as the "backup" if my current phone ever fails on me.
I'm sure you could find an iPhone 5/5s - for cheap to serve as an emergency backup.