A more thorough explanation:

The firefighter's rule is a legal principle that states that a firefighter, police officer, or other emergency professional cannot sue a person, usually a property owner, for unintentional injuries they suffer while responding to an emergency caused by that person.

For example, if a firefighter is injured while putting out a fire caused by a property owner's negligence, the firefighter cannot sue the property owner for damages. Similarly, if a police officer is injured while responding to a crime committed by a person, the officer cannot sue that person for damages.

The firefighter's rule is based on the idea that emergency professionals assume certain risks when they choose to enter dangerous situations as part of their job. It is also intended to prevent emergency professionals from being deterred from responding to emergencies out of fear of being sued.