I am using it for having a hot water near my bed to make my babies milk warm. I was not expecting in 5 hours to have that boiling water but it was hot! And i think i will use it as a coffe cup as well when i will have to take my baby to nursery. I did not try to keep the water for 10hours how ir it should be holding the heat but i will try soon i think. Im glad that i bought it. Thanks for the good product!