Are you going to GBMC? I know that families can stay for a small fee at the Ronald McDonald House http://www.rmhcbaltimore.org/about-our-house/staying-at-the-house-faqs/. Also the closest hotel to GBMC would those on Charles street or in the towson area. http://www.roadsideamerica.com/hotels_motels/poi/65259.html Stay away from the Inner Harbor as this would be expensive. If you have any questions let me know. Does your son have EDS?