Dont have gl router for checking temperature on this time around me.
I can tell you from two equal PCs:
PC are playing a video: CPU 52°C, (crit. 105°C, thats mean, CPU will stepp down a little bit the speed, by 105°C for preventing demages)
One other PC, which change the resolution from a Video on this time, are allway around 103°C (crit. 105°C, thats looks for me, this CPU are already stepp down a little bit for preventing from temperatures higher than 105°C)
True maybe not accurate, but at least information is representative.
Since I use both 2x routers together only at home, I put them in small 20x20x20 metal ikea box, temperature went down and not increasing more than 44C.
I have also installed a fan in it in case of with xiaomi termometer
I recall loading some temp monitor software and also found it sitting at 44-45. only thing that comes to mind would be dropping down core numbers to achieve that but I yet to confirm it.