Just throw on your Sandals of Summer - Item - World of Warcraft and activate the fire, cast your Winter Veil Disguise Kit - Item - World of Warcraft . Poof you're a tosty snowman.
PS. You can also use Vestment of Summer - Item - World of Warcraft while in furbolg form to make it look like you're casting a long fireball
Have fun
SS added for those of you who missed it.