If we can avoid massive collective issues that would be appreciated as there is very little agency the individual has to address those and that helpless ess can often extend to the more solvable individual matters we all grapple with but also occasionally rise to conquer.
I don’t have enough knowledge on the subject to suggest a solution.
But asking a question along a tangent since you mentioned heat:
Which colour does your van and its roof/interior have?
If its a darker colour, maybe trying a lighter colour would help reduce the heat gain?
https://www.youtube.com/watch?v=W_2lsMXR_wo
https://www.youtube.com/watch?v=qLVNjS403M8