[RosieCotton]

That would work...though I'd have to dump it into something to heat it, or heat it before putting in the Thermos.

I should probably do that. Wish they weren't costly, but I guess you buy it once and can use it for a long time.

[JenB]

Or, put it in the container the night before and freeze it. Then leave it out, or in a fridge, at work, and any remaining ice will melt in the microwave when you heat it up.