Hyperthermia in 2.9.1c

I was recently playing on my rlcraft server and i am in need of blaze rods to finish crafting the Dragons eye. So i went to lava to spawn some mobs and get what i need. I summoned my afrit so i can have fire res while fighting to make it easier. And i start taking hyperthermia damage? dosent fire resistance make you immune to hyperthermia? Did they change it or something as in 2.8 i remember with the dragons eye hyperthermia wasnt a problem.