What does a "1" displayed on the heat and ventilation board during winter indicate?

The "1" displayed on the heat and ventilation board during winter signifies that one point of heat should be operational in each car of the train. This is crucial for maintaining a comfortably warm environment for passengers during cold weather, where insufficient heating can lead to discomfort and potential safety issues.

In a train’s climate control system, the display is a guide for the train operator to ensure that all necessary heating measures are in place before departure. This setting helps ensure that even if outside temperatures are low, each car retains an adequate temperature for passenger safety and comfort.

Understanding this function is vital for train operators to effectively manage the heating system and provide a pleasant travel experience in winter conditions.