Which one of these can you freeze and thaw?
I’m not sure I want to use one of those thermos cups that is only for freezing water.
I would rather use a thermos that is reusable, which could be a thermo-cooler that can be used to keep a cool refrigerator in your home.
However, it is worth mentioning that if you have a thermonuclear bomb on your desk that you want to keep it in a safe place that you can reach from the outside, you might want to consider purchasing a thermic pump that can hold up to 20 liters of liquid at a time.
The pump is also great for dispensing liquids from your kitchen cabinets to your freezer.