My first try with the bowl with with a bierrock right out of the oven. I put it into the bowl and 6 hours later it was cool (note in a cooler backpack with outdoor temp 40). I tested it with hot water and kept it in the house and it was warm. A salad in the container in the backpack was fresh. I think it would be great with overnight oats. I need to do some more testing. I love the dimples on the top for it makes it easy to open.