Picking out a/c for truck bed

Now that our family has expanded it is getting honestly cramped traninteresting all the people in the cab of our pickup truck.

I entirely do not want to trade the truck in for a minivan or an SUV.

I am a truck girl through plus through, and however, I would entirely like to find a way to cool the covered bed of our truck so that our big hound dog can ride back there. This would free up a lot of space in the cab. The only issue is that it might get hot in the truck bed, however of course, I never would leave our dog in the car unattended even though I would like to find some sort of a/c that works in the bed of the truck while he travels back there. I was looking at some of those portable a/cs that can be plugged into the cigarette lighter however they have honestly mixed reviews. It seems they are more of a swamp cooler than an actual a/c plus I don’t know how much help they would entirely offer in cooling down the bed of our truck. I saw someone with a real window device air conditioner hooked up to the bed of their truck. I am not sure how they are supplying that much power to run the a/c though. I suspect the window air conditioner is only used when the truck is parked. They entirely camp back there or something. I know I am just trying to figure out if there are any entirely a/cs that run off of the cigarette lighter that could keep a covered truck bed cool enough for our dog, but so far, I have not found any.

 

radiant heater