This phrase is commonly used to tell someone to settle down before they become overly angry or upset. Italians tend to use this phrase more often than other nationalities.
Amanda: I skipped class today and I just realized I might have missed a test!
Sitting in your room, and a girl/guy walks by that you notice is very good looking and you are with other people at the time so you either think to yourself or yell out loud...Can I Get A Hot Tub!