Today I tried using the same Stanly thermos again. This time I heated one cup of water and poured in it and dumped before putting my coffee in. I didn't fill completely only a large coffee cup of hot water and I didn't fill completely with coffee. After about the same amount of time as it had been the other day I poured my cup of coffee and it was cold again. This was carried in the back floorboard of a heated pickup for about 2 hours. On a hot day it would have been a cold drink. It wasn't warm at all. I did notice when I poured the hot liquid in I could feel the warmth on the outside of the bottle and though then there is no way this will stay hot.