The heaters fro cold storage are an optional features for the unit. The EV100 controller will work in the cold temperature but in the operation you have the lift trucks needs to be equipped with the optional cold storage/freezer protection - heater - fluids (hydraulic, gear case, etc.
I suggest you, & it is your best bet, contact your closest Crown lift truck dealer to get the exact details of what is needed in your operation - they are the experts on this equipment. Give them your operation details (time in freezer - time out, etc) as well as truck model, serial number & the controller model.