True or False: Crew members must alert their team when the heads-up display indicates a change in cylinder psi.

The statement is true because alerting team members about a change in cylinder psi as indicated by the heads-up display is essential for safety and operational effectiveness. Crew members rely on this information to ensure that they are managing their air supply appropriately, which is crucial during firefighting and rescue operations.

When the psi level changes, it can signal a decrease in air supply that might affect the team's ability to perform their tasks adequately. Promptly communicating this change facilitates timely responses, such as conserving air or exiting hazardous environments if necessary. It fosters a culture of safety and awareness among team members, as everyone can stay informed about critical resources during operations.

In contrast, other choices suggest conditions under which a notification might not be necessary, which undermines the protocol of mutual awareness and quick response that is fundamental in emergency situations. Keeping all crew members informed regardless of the setting or the extent of the change ensures that safety remains the top priority.