Have you ever had the realisation that you brought along a tasty instant oats snack but didn't bring a bowl to make it in? Reddit user Klacky offers up a simple solution: cook it in the packet it comes in.
If you flip the instant oats pack upside down and open it, the bottom portion (which was once the top) will work as a waterproof seal. You can then very carefully pour hot water in and the bag should remain waterproof. You're pouring boiling water into a paper bag, so test the packaging with lukewarm water before you do anything else.
It's not clear what exactly the bag is lined with, but there's a good chance you don't want to be ingesting it every day. Still, for those rare moments at the office or on a camping trip, it works great.