Hard hat: protects the head from falling objects
Leather gloves: protects hands from cuts and debris
Goggles: protects eyes from dust and air borne debris
N-95 respirator mask: prevents from breathing in dust, hazardous gases
Yellow vest: allows others to recognize that you are a responder and not a victim
Because it hydrates them quicker I believe
Qi. (che) [Chinese] chi or ch'i; one of the basic substances that according to traditional Chinese medicine pervade the body; a subtle influence or vital energy that is the cause of most physiologic processes and whose proper balance is necessary for maintaining health.
i hope this helps