Final answer:
When an incident increases in scope and complexity, the incident commander should consider requesting a second incident commander to assist him or her.
Step-by-step explanation:
When an incident increases in scope and complexity, the incident commander should consider requesting a second incident commander to assist him or her. This is because managing a complex incident may require additional expertise and resources. Having a second incident commander allows for a division of responsibilities and better coordination of command functions. It also helps to ensure that the incident is effectively managed and that all operations are carried out smoothly.