You need a HEATER FOR YOUR CHICKEN COOP.
After trying many different types of electric heaters here in TEXAS, over 15 years, we are using the :
Walmart- Sunko / Hyper Tough heater,
Tractor Supply - RedStone Heater.
Northern tool - LifeSmart , They are the same heater, different name...
( Sunko Black 1500w Heavy Duty 2-Setting Electric Utility Space Heater with Thermostat. )
With the nightime LOW at 12deg, Set the thermostat at 70 and forget it.
Get ready for EGGS all winter.