Petrolburner
Explorer
What about a shade awning EZ-up type thing you pull out and put over your van if there is no shade available? Shade seems to be the best thing, but often there isnt any available. Kind of a lot of work but if you are going to be out of the van for a few hours then it might be worth it if you cant bring the dogs.
I would think you'd be better off making awnings out of the shade cloth. Those EZups can do a lot of damage if they're not securely staked down. If you're going through the work of staking one of those down, may as well make a shade cloth awning for less money and less weight.
The big thing is to manage the airflow. Pull air in from the shaded side and exhaust it out the top. I like the idea of intake holes in the floor, there's always shade there. Then if you didn't have the time to setup the awnings, you could leave the windows closed and pull air from underneath the van and exhaust it out a roof fan. Remember that the asphalt is hot, and the underside of the van will be hot from engine and exhaust for awhile though. I'm wondering if I'd be better off with a fantastic fan on the big square upper section of my rear door, or on the roof? Any thoughts?