This is from a photo series at an aid station in Italy in 1945. One shot shows stacks of litters for the litter teams to grab (assuming they left the patient on the litter they used coming in), as well as a small pile of crates & cartons for the medics to refill their bags - mostly Carlisle bandages, etc. there was a stack of blankets available, too. In this series of photos, the Aid Station and the Clearing Station were co-located - casualties were brought in, stabilized, and moved by ambulance to a field hospital about 5 miles back.
A better example is seen here - there are about 30 shots taken if you can find the full set.