UPDATED April 20th, 2018
If you just scratched your head for a few minutes trying to remember what a hot water bag is, then we’re right there with you. We had to Google it. Turns out a hot water bottle is that plastic sack that looks kind of like a whoopee cushion and kind of like an ice pack that your grandmother used. It is used to administer heat or cold to your body, similar to a heating pad or ice pack, yet it’s incredibly safe because it involves zero electricity.
They are so safe even pregnant women can them. The true old-fashioned bottles are made of metal or ceramic, but according to Livestrong.com, “it’s generally preferable to use plastic or rubber bottles that are soft, flexible, and easy to curl up with. Odorless plastic is ideal if you want to avoid the strong smell of rubber, and it’s best to use a seamless bottle because they are less likely to leak.”