We expect the frosts to -38C (-36F) outside, now of course also not hot -35C (-31F) . Therefore, I’m not risking reducing the heating threshold by 1C degree in greenhouse, from +13C (+55F) to + 17C (+63F), while I’ll leave +14C (+57F) - + 18C (+65F), while now the window temperature is + 7C (44F), and the temperature of the nearest orchids are +14C (+57F) - +15C (+59F).