There are a number of exterior safety considerations. It is impossible to see directly behind the vehicle without a back-up monitor. They are available in color or black and white. Most have 10 through 0 marked on the screen to help evaluate distance to an object in the monitor (10 means you can back up closer, 0 means you just hit something.) Side view mirrors should be heated to prevent fogging or ice build up. They should also be easily adjusted by the driver from the driver's seat.
Consider how patients will enter and exit the unit. Entry door monitors are an available and popular option. This enables you to see who is approaching the vehicle. Some programs install remote door locks as an added security measure so they can control who opens the door. Exterior entry lighting is also recommended for the entry door. Do the stairs into the van have railings, and if so, are they on both sides? This can make a difference when treating frail elders or others with mobility problems. Will poor weather impact your operations? Do you need an awning to protect from rain, ice and snow?
Can the clean water, sewage drains, compressor, generator, and controls for leveling the unit be reached comfortably?