Speak with Lurielle at the Frozen Glade.
For generations, my people have told tales of frost nymphs cavorting in glades hidden away in the wilderness. I used to search for them as a child, against the advice of my parents, until I nearly froze to death.
These days, it isn't necessary to comb the forests for them. They've decided to reveal themselves for reasons I can only guess, but I don't think the change can be ignored. Venture southeast to the Frozen Glade and seek out the nymphs, but beware; you will pass the Twisted Glade on your way.