As Canadians, we can completely relate to extremely cold temperatures. The LongMill can safely be operated at sub-zero temperatures. Although we haven’t done specific testing at low temperatures, the LongMill’s tolerance for low temperatures far exceeds what you as the operator are likely to handle. We have many reports of customers running their machines at sub-zero temperatures with no issues.
As for high-temperature environments, you may experience issues running at high ambient temperatures above 55C or 110F. This is primarily due to the maximum operating temperature limits of the motor drivers and motors themselves. The maximum measured temperature delta of motor drivers operating at full capacity is around 25C above ambient temperature. Running your drivers at 55C ambient would run drivers at around 80C or higher (depending on additional resistances at the higher temperature), which is close to the 100C max operating temperature for the motor drivers.