Raise (Veggies on) the Roof
The roof garden provides another two-fer: happy planet, healthy patients.
Green roofs can be included on almost any structure these days, even dog houses. Most hospitals are big, and if they're built with a roof garden (or three) in mind, they can probably grow enough produce to feed Great Falls, Montana. Well, approximately.
Putting plants on the roof increases the carbon dioxide/oxygen exchange that we oxygen-breathing humans so appreciate. Patients and the people who visit them in the hospital all can use the calming effect of visiting a nicely tended garden during otherwise rotten times. Employees can get their green thumb on and have a lovely little lunch spot that doesn't smell like bodily fluids.
A green roof also isn't a painted-black roof, which like the parking lot just makes everything hotter. If you can't plant some tomatoes on the roof, at least paint it white to reflect the heat and keep the interior of the hospital cool.