My sleep setup lowered my resting heart rate to 39 bpm

I found my perfect sleep setup to lower my heart rate: - AC at 18°C - @eightsleep at -4 (night) +2 (dawn) My avg. RHR is 41 if I use one or the other. Both combined drop my RHR to 39, and I feel even better when I wake up. Also, I don’t use a blanket. Just 2 bed sheets, so it’s really thin. Temperature is by far the most impactful factor on my sleep. CO2 ppm in the room, hot shower, early meal before bed—none of this really impacts my sleep. But if I feel even a little too hot, my sleep quality drops.