Heater bees vibrate their abdomens, or they can decouple their wings to use these muscles to bring their bodies up to 111 degrees Fahrenheit.
It also determined that the queen leaves certain cells in the brood area empty because after the heater bee is heated up, the heater bees crawl into the cell head first using the cell to warm the surrounding cells in which last up to 30 minutes as the body temperature cools back down.
Heater bees can also regulate by standing over and pressing their thorax against a developing capped pupa.
Depending on the hives needs the heater bees can adjust the temperature of certain cells to accommodate the needs of the hive such as the need for more foragers.
Information is from Today I found out….and Honey Bee Suite.