A STRANGE DARK BLUE HEAVY DENCE FLASH, my lungs felt very warm and I became light headed and my face was flush

A STRANGE DARK BLUE HEAVY DENCE FLASH!!!!!! I was trying to make extra money on one snowy season by shoveling sidewalks and mailboxes while my brother was plowing driveways. The snow was coming down heavy with low visibility and it was very cold night with wet shoes and pants, I was shoveling for approx. 4 hours around 3:30 am ("I was not tired or was I drinking")It seemed that the clouds were low with 2 feet of snow and it was very, very quite in this area of this middle class neighborhood.
I'm not sure what the elevation is up in Randolph NJ but the area is wooded and hills. As I was shoveling a Dark Blue flash emitted from the sky (not a beam or a laser type, no rolling thunder, rain, or lighting.) Just a surrounding Dark Blue heavy dence flash. I was standing and bending over. The best I can describe it seem to lit the whole area. As far that I can tell and trying to remember it lasted approx. 3 sec's. Now I felt startled, and a signigifiant change in temperture. It felt that my heart has stopped. (more like a scared feeling) I felt a warm feeling and I started to cough,(coughing fit lasted for approx. 5-10 Minutes.) I remember then my area of inside my lungs felt very warm and I became light headed and my face was flush(lasted about 4 minutes.) I'm not saying it was a UFO or whatever! But It scared the day lights out of me, and my brother saw it too but he was in the truck. He did not experience what I have felt. I can't explain it.