For our temperature testing, we measure the peak GPU core temperature under load. A reading under load comes from running Cyberpunk 2077 for 30 minutes.
As for temperature testing, both the Dual and Eagle are more than a match for the RX 6600 GPU. Both saw peak temperatures stay below 60C, which is quite incredible really, while the Dual's hotspot peaked at 67C compared to 73C for the Eagle. I'd imagine most of the RX 6600 cards will be using the same cooler designs as the RX 6600 XT models, so we would expect better thermals as the 6600 is a lower-power chip than the 6600 XT.