I liked how it seemed to reward creating nice symmetrical designs with the nodes, which felt really satisfying to dissipate the heat efficiently!
I had fun trying it out, but towards the end I encountered a few bugs that ended my play session with a soft lock (no win, no meltdown even with both bars full), but not sure what triggered it. I was just experimenting and testing out the mechanics and noticed a little bit of unreliability with the drag n drop system and delete tool as well, and I was just curious if I could figure out what was going on. Maybe the video of my play session will help you find out the bug that are still sneaking around that might have gotten triggered by something I did.
But good job on the overall design and the idea! I really like where it's going!