He may not have been Polish.

.

On a serious note. An automobile with the air conditioner on for a long drive, with recirculating air, can also result in an area of low oxygen.

Not that the above has anything to do with that here, but something interesting for hotter times.

Is that a wheelchair symbol hanging from the mirror? The driver may have had a lot more wrong with them, and the mask blocking the oxygen certainly would not have helped that.