Caravan Wall Vents

If you're planning on living in a vehicle for any period of time, even just briefly, ventilation becomes important. If you're using gas appliances in there (and that includes water heater and gas fridge, not just a cooker hob) then ventilation is necessary to stay alive.

Wall vents that are fitted to motor caravans and similar coach-built vehicles are not exciting things, but they are lifesavers.

Some incorporate a mesh to keep insects out, a couple (designed with 12v/240v fridges in mind) have a 12v fan to force circulation and thus aid cooling when it's really hot.