Individual bees are cold blooded. At about 42 degrees F, bees can't move because their muscles are not warm enough, per The Beekeeper's Handbook, 5th ed., 2021, Diana Sammataro & Alphonse Avitabile.
However, the colony as a whole is a warm-blooded superorganism. Bees in winter cluster can keep the queen at 68-70 degrees F in subzero temperatures and when the colony starts to raise brood at the end of winter, the colony must keep its core temperature around the brood at 90-94 degrees F no matter how cold the ambient temperature.