"Cold war" is an example of what you are looking for, yes.
Along the same vein: (see what I did there?)
- cold-blooded killer
- the common cold (used so much its not even a metaphor any more)
- have cold feet (nervously reconsider)
- left out in the cold (neglected or abandoned)
- out cold (unconscious)
- hot on the heels (closely behind)
- have the hots for (be sexually attracted to)
- in hot water (in trouble)
There really are too many to provide a list. Those are just the common (American) metaphors that I could think of involving hot/cold in a few minutes.
As you noted, there are many, many metaphors people use in their everyday speech without even realizing they are using metaphors.