It’s doubtful that putting them in outdoor heat will kill bedbugs; you need to put bedbugs in a dryer for 90 minutes, and maybe longer than that. High heat in a dryer is about 125-135 degrees F, and it’s enclosed, so there won’t be clouds, shady, wind, or whatever to give them a chance to survive - and bed bugs are unbelievably good at survival. Just shockingly good. You can’t fight bedbugs with the attitude that “There’s a 95% chance this will work.” You have to KNOW what you’re doing.
I found it was really a multi-pronged strategy that took care of my bedbug problems. Contact spraying immediately killed the ones I could see. I then went out and got a mattress cover and box springs cover to trap the ones that were probably hiding somewhere I couldn’t see. Those two steps helped right away. But the ordeal was far from over.
The hard part is figuring out where they had spread, and how I could prevent them from biting me at night. I thought, as long as I can just keep the little buggers from biting me, it’s okay, right?
Actually, no. This is where I learned how to defeat bedbugs.
Part of my strategy was to allow the remaining ones to bite me, but first, they would have to crawl through diatomaceous earth. They’d get their little blood meal, but they’d also die 24-48 hours later. I sprinkled diatomaceous earth against the baseboards, so that the bedbugs hiding behind the walls, would crawl through the barrier. I also put my bed away from the wall, so that the only way they could get onto my bed would be to crawl up the wall (and again, through the diatomaceous earth) and then drop down in hopes of landing on my bed. I put the legs of my bed in cups filled with diatomaceous earth. Basically, I made it so that there was a very high likelihood that bed bugs crawled through a substance that rips their exoskeleton open and kills them slowly, but inevitably over a 1-3 period.
I’m not saying my solution would work for everyone, but I would at least consider it. The key to defeating bed bugs is to know your shit. Know everything you can about them before making important decision. One thing I’d say is, I was somewhat lucky in that we didn’t have a major infestation. Once an infestation spreads to multiple rooms and especially multiple levels of a residence, forget it: you have to call the exterminator. They’re the only ones who can handle massive infestations.