Originally Posted by
_kurt
As
TWA884 said it’s absolutely possible, and will almost surely be quicker than waiting for a bus. Be aware that to do it landside, part of the walk will be outside on a covered sidewalk so be prepared for Chicago temperatures. If you’re truly on a connecting flight why can’t you check your baggage through? Or is it two separate itineraries?
One more small piece of advice to add: It's best to go up to the Departures level for the outdoor walk over to T3. Easy peazy.