In this chapter:
(1) "Emergency medical first responder" means an employee or volunteer of the state, a political subdivision, or an emergency medical services provider who provides urgent on-site medical care to the sick or injured.
(2) "Firefighter" includes a volunteer firefighter.
(3) "Peace officer" means a peace officer commissioned by the state or a political subdivision of the state under Article 2A.001, Code of Criminal Procedure, or other law.
(4) "Next of kin" means the relative in the nearest degree of relationship to a deceased person, including the person's spouse, child, parent, or sibling.