This little tea thermos is great when it is beastly cold…I work in a 100-year-old building with wonky heat, and it does a very good insulative job. Of course, the plus is the screw-in strainer in the lid, so you can start with the good stuff in the a.m. and get reruns later in the day :)
After a few months of use, my only critique is that the round rubber seal around the lid sometimes comes out when I wash it (due to the strength of the vacuum seal) and I have to poke it back into its groove. Small price to pay for good warm tea all day.