Not as hot
My daughter has been using an old red water bottle for stomach cramps and general pain. It's pretty plain, so I thought she might enjoy this hot water bottle, as it has a soft and pretty cover on it. Imagine my surprise when my daughter tossed the bottle to me the next day and said that it didn't help at all, and she wanted to use the old one instead.  As best I can tell, the cover insulates the water bottle, keeping some of the heat in. I suspect that it works fine for those who are not already wedded to an uninsulated water bottle, but it was not a hit at my house.
Rating: 3 stars