fakaltnisht T-Shirt

fakaltnisht...growing up I heard my grandmother use this expression when she was upset with my grandfather. Always a lady, a curse never rolled off her tongue though the way she said this sounded a bit vulgar. When we would ask she always said "it means don't catch a cold" and we had to believe her. We had doubt.Many years later and after she was no longer I asked of cognoscenti. Finally, recently, I got informed confirmation that indeed the phrase means don't catch a cold;