I made a Thermos Snuggie out of an old Survival Tarp and some Super Thinsulite that keeps the sucker hot and toasty for 8 to 10 hours. My thermos is at least 25 years old.

New cap and gasket is also the key to keeping things hot.

Keep it in a bag not on a surface that will transmit the cold to the Thermos body.

It was 10 degrees the other night and my Coop had a Steam Line break and I am the poor SOB on weekend duty. I spent 4 hours with the emergency crew digging out and exposing the line and prepping for the plumbing crew to fix at daylight. When they built the place they didn't install Thrust Blocks at the 45 and 90 connections so every year we lose 1 or 2.

When I opened up my Thermos to share the love, the coffee/bushmills mix was as hot as when I made it at 12:30 AM.

The pipe fitting was changed by 8AM and we placed 1/2 CY of Quickcrete and 2 U rebars as a Thrust Block and the heat was back on by 9:30AM.