Cool and Cold can both be used as a verb,adverb and adjective! The meaning changes depending on the usage. Cold is mostly used to describe temperature or someone's attitude!
1.Russian winters are very cold.
2.He was very cold towards me.(Here cold means not-friendly just as warm would imply friendly)
Cool is used to describe the temperature or anything/anyone that is good.
1.It is very cool in Russia, in this time of the year.
2.He is a cool guy.(He is a nice guy)
I hope this was helpful :)