Ever since I started using these warmers at night, I have noticed that my feet are definitely more cozy. However, the problem lies in their loose fit. They tend to roll around and even slip off my feet, which ends up making me fidget throughout the night. This, in turn, affects my sleep and keeps me awake in a different way than just having cold feet. It would be great if there was a way to adjust their size to ensure a snug fit. On the positive side, I do appreciate the fact that these warmers are reusable, which helps reduce waste. But, I must caution you not to overheat them for more than a minute, as they will develop a lingering smell of burnt popcorn. It's not an unbearable odor, but it's one that tends to stick around.