Notwithstanding any other provision of law, no volunteer firefighter or volunteer emergency medical services personnel shall be liable for any injury to persons or property arising out of the operation of an emergency vehicle as defined in § 46.2-920 when such volunteer is en route to respond to a fire or to render emergency care or assistance to any ill or injured person at the scene of an accident, fire, or life-threatening emergency and the emergency vehicle displays warning lights as provided in § 46.2-1022 or 46.2-1023 and sounds a siren, exhaust whistle, or air horn, unless such injury results from gross negligence or willful or wanton misconduct. The immunity provided by this section shall be in addition to, not in lieu of, any other applicable immunity provided by state or federal law, including § 2.2-3605 or 27-6.02.