Bring a camera, it could make good (if wildly disturbing) reality TV. You wandering Medieval England, wearing a face mask, gloves and a Tyvek suit, with your completely unknown accent, trying to convince a whole society “you’re doing it all wrong!”
Heck, why not just save a ton of photos and videos on a local hard drive about how we live today, and film their reactions. I can imagine the episode name already "SHOWING MEDIEVAL ENGLAND CITIZENS YouTube VIDEOS!! (RIOT STARTED!!)"