Board Thread:Naruto Discussions/@comment-38792431-20200226192508/@comment-32685487-20200227174327

The words used were "Skin like steel, and blood like iron" to decribe the 3rd's Ability to survive the heavenly transfer without some sort of healing ability(like Tsunade). So it's safe to say that the 4th Raikage had that on top of his Lightning Armor.