Cold foam, also known as High Resilience foam (HR foam), is by far the most used type of foam in mattresses. In almost all mattresses there is at least one layer of cold foam. There is also a lot of experimentation with the addition of other materials, such as gel components. As a result, the properties, qualities and prices of mattresses with cold foam vary enormously. Cold foam is available in many qualities. Incidentally, the name has nothing to do with how cold or warm the foam feels, but with the way the foam is produced.