WHILE DRIVING MY VEHICLE IN CONGESTED TRAFFIC, THE AIR CONDITIONING UNIT RELEASED ALL OF THE R-134 A INTO THE ENCLOSED CAB. I WAS EXPOSED TO THE SUBSTANCE FOR QUITE AWHILE BEFORE I REALIZED WHAT HAD HAPPENED. I FINALLY PULLED OFF OF THE ROAD, AND EXITED THE VEHICLE. I HAD SEVERE HEADACHES AND NAUSEA FOR A COUPLE DAYS. IF I HAD AN INFANT IN THE VEHICLE, THERE COULD HAVE BEEN A DEATH DUE TO THIS MALFUNCTION. *LA