That depends on your Armor Rating though. I took a little taste of it too on my lvl 81, 2 Legendary Dragons can kill you in a heartbeat.

i had the reached the maximum armour rating and i get killed in about 1 second from ice or fire when a blood dragon attacks, this was at level 81 with 200 health on master.
its a good thing i have fast reactions and lots of healing potions.