An officer or employee of a state or local agency, or a volunteer acting at the direction of an officer or employee of a state or local agency, is considered for purposes of Section 437.222 to be a member of the Texas military forces ordered into active service of the state by proper authority and is considered to be discharging a duty in that capacity if the person is performing an activity related to sheltering or housing individuals in connection with the evacuation of an area stricken or threatened by disaster.
Tex. Gov't. Code § 418.006