Hiccup: "[Your Viking's Name], are you feeling okay? You look a little flushed. You need to be mindful of your health. The harsh elements and temperature on Icestorm Island can be really dangerous if you don't take the right precautions!
Luckily, Gobber came by on the island. He's no Gothi, but he'll be able to fix you up if you're feeling sick. He went up near the Speed Stinger's territory. Please, do me a favor and talk to him about your health."
1- Talk to Gobber
Gobber: "Hello, lad/lassie! Beard of Thor, you look terrible!
You're shivering like a wet yak in winter! Well, it's no wonder. You're in the middle of this blizzard in those flimsy clothes! You need to head back to Berk right away, and get out of this harsh climate for a while. I'll help you there."
2- Fly back to Berk
Gobber: "You can always hug [Your Dragon's Name] if you really need heat, but you need something a bit more permanent if you want to go back to Icestorm Island.
If you aren't careful, you can easily get frostbite or hypothermia. Frostbite is a skin injury from prolonged exposure to cold temperatures. It usually occurs on the nose, fingers, and toes. You can also get hypothermia, which is the condition of having low body temperature caused by prolonged exposure to cold temperatures.
What you need is thick, thermal clothing to keep yourself protected. Go talk to Trader Johann and see if he has any arctic-appropriate clothing for you to wear."
3- Talk to Trader Johann at Berk
Johann the Trader: "Thermal clothing? Indeed, I have a set right here. I picked it up from an explorer who decided to retire to a tropical island. Since you helped me figure out how my boat was destroyed, I will give you this set for free! You are a loyal friend, [Your Viking's Name]. I appreciate your diligence!"
Gobber: "Did you get new clothes from Trader Johann yet? Put them on and come find me so I can take a look! Open your Journal and switch to the customization tab to change your clothes."
Note: You now need to click on your Viking and press the Customize icon.
4- Talk to Gobber
Gobber: "That's more like it, lad/lassie! With hypothermia, a person's body temperature drops well below the usual 98.6 degrees Fahrenheit and their body can't work properly. It can be quite dangerous! You need to bundle up here and protect yourself from the cold at this island. Now you should be able to explore any part of Icestorm Island while staying hypothermia and frostbite-free!"