The principle is excellent; a few minutes in the oven is heated (normal oven for me) and heat is restored some time; you can do the reverse in summer and it is also why I bought it. The problem is that the cushion is not filled well enough to be effective; it shows in the time remaining hot or cold ... Too bad because it hugs the place to warm up and I find it very comfortable. That's why I put only 4 stars. Otherwise it would be perfect!
