Pretty sure Project Gorgon has zones that are weather extremes that require special gear/consumables.
I think special gear can work as long as you have a really strong gearset/gear storage system. Nobody wants to play inventory management for shit they HAVE to lug around and sifting through shit only to realize you forgot you're wearing your fire resist earrings during raid night is not fun. The challenge should be the intention of the player to do something, not in their ability to fight your shitty ui/inventory system to make it happen. The armory chest system in FF14, expanded for different styles of gear would probably work. Even better, set up an armor rack system in your instanced housing where you can store the armor sets in the 'real world' and then just have a goofy d&d style magic closet to access them when not at home.