This replacement shuts off a foot inside your house and therefore won't freeze unless it's freezing inside your house! These are particularly easy to replace in unfinished basements, but finished basements need them more because more damage can be done! Click on image for product link.
Well, it's just in the single digits and this hose bib leaked into an icicle until the water froze inside the supply pipe. The pipe may now be fractured and when it thaws could cause a flood. If you don't have the devices above then you need to shut off the supply to your hose bibs and then open them so any water in the pipe drains out so there is nothing to freeze when it gets this cold.