I made a voyage into the frozen north to hunt for star metal ore. I never did find any, but I did come across the Frost Temple:
I figured while I'm here, I might as well have a look inside. On a side note, you wouldn't think that Lemurian Royal Garb would provide cold resistance by looking at it, what with all the exposed skin, yet it does. I'm assuming the logic behind that is the same as a chain bikini protecting against physical attacks.
The frost giants in and around the temple are some of the easiest high level enemies I have ever encountered. Outside of mountain goats, they may be the easiest enemy located in the entire cold region of the game. 95% of the damage you see thet I've taken in the screenshot above was from cold exposure, not physical damage from the giants.
Hrugnir, the Frost Giant King:
Much like the common frost giants, Hrugnir is extremely easy to fight, provided you are wearing armor that allows you to dodge roll (light or medium). I would go so far as to say that he's the easiest boss I've fought, even easier than the giant crocodile in the cave with all the brimstone. I mean, I'm sure he hits really really hard, especially with his impressive looking charge attack, but that doesn't matter if he never hits you. I didn't even bother cheesing him with snake arrows, and there's plenty of room to kite him for days in his throne room if you want to take that approach. Cutting him down with my axe was very easy.
I wound up coming back to the Frost Temple later on another expedition hunting for star metal ore (successful this time!), but also because I wanted to use the Frost Temple Smithy located there now that I knew what I needed to forge items there:
I made this Black Ice Broadsword and a Black Ice Pick. These black ice weapons and tools can only be forged at this smithy, so if you plan on going to the Frost Temple, do yourself a favor and bring along a hardened steel sword and a hardened steel pick (you will also need black ice, but there's tons of the stuff to mine inside the temple). The black ice broadsword pictured above might not be the prettiest sword ever made, but it does massive amounts of damage. You won't ever need to return to the smithy once you forge everything you need, you can repair black ice weapons and tools with black ice and hardened steel yourself on the go.