Late in the third period, Wheeler had the puck and was headed up ice down the left wing. As he reached the Dallas Stars' bench, he was nudged by Colton Sceviour. At that same moment, however, the door to the bench was open as players had just completed a line change.
Wheeler hit the edge at full speed, chest first.
He remained on the ice in some serious distress for several minutes. Considering the speed at which Wheeler was traveling and the fact it's basically just exposed steel and hard plastic there, he's relatively lucky that it hit where there should be at least a little bit of padding instead of his face. That thought probably didn't dull the extreme pain Wheeler must have been in at that point.
After the Jets scored to get within one, Wheeler managed to return for the last shift to try and help score the equalizer. That's some serious toughness there.
The Jets ended up losing 2-1, but they'll be happy Wheeler wasn't more seriously injured on that bench.