U.S. Coast Guard Commandant Instruction (COMDTINST) M3710.1 (Series)
My copy is out of date and I haven't found one online (though I'm sure it's out there). I'm sure this hasn't changed.
Chapter 7.A.3
A.3. Flight Clothing
All crewmembers in Coast Guard aircraft, including those serving with the Coast Guard on exchange, shall use protective clothing as follows:
A.3.a. Flight suits and Boots
Aircrew personnel shall wear fire-retardant flight suits or anti-exposure coveralls and flight boots when engaged in all ground and in-flight operations.
Mission-essential personnel and passengers should wear fire retardant flight suits for operational, non-transport missions.
A.3.b. Flight Gloves
Rotary-wing (R/W) flight crews shall wear gloves when engaged in all ground and flight operations.
Multi-engine fixed-wing (ME/F/W) flight crews shall wear gloves during all ground operations, takeoffs, and landings.
Mission-essential personnel and passengers should wear fire retardant flight gloves for operational, non-transport missions.
A.3.c. For R/W aircraft, aircrewmembers within close proximity to a turning rotor system, including persons being hoisted, shall wear a helmet.
Blah, blah... there's more, but that ought to cover most of what you need...