Help: Looking for a third-party setting book!

Hi, I'm making this post to ask if anyone knows the name of a third-party book.
I don't remember the title, but I do remember that the book features a completely different setting. Here are the key things I recall:

• An immortal Sultan who has a heart of stone.
• Hooks and advice on how to roleplay the NPCs (e.g., portray the Sultan as either a tyrant or a benevolent ruler).
• Rules for weather and how it affects the PCs.
• An extreme cold weather effect that can shatter even magical weapons and armor.

I'm not sure if this is enough to identify it, but any help in this search would be greatly appreciated.
Thanks!