The act of dancing in a club, during the winter, with a coat on and your hood up while consuming alcohol. Similarly the dance resembling the "robotdance."
The people decided to skip the coat check because the temperature was cold inside the club. Instead, they proceeded to go onto the dance floor and do the Fetty Dance.
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!