Frostweave Bandage

To learn the skill you need 350 skill in first aid. It allows you to aquire skill until 450. When you skill up to 390, Manual: Heavy Frostweave Bandage can be acquired. It is a world drop so dont worry about farming for it. Doing any instance will propably wield it for you.

Frostweave Bandage trainers listed below.

For Alliance:

Anchorite Yazmina - Valgarde Keep (Howling Fjord) -- Found at the Bonfire, near the dock. --
Brynna Wilson - Valiance Keep (Borean Tundra) -- Found next to the Blacksmith Trainer, near the Sparring Footmen and a very interesting and curious "thing". --

For Horde:

Sally Tompkins - Vengeance Landing (Howling Fjord) -- Found on the top floor of the Building, next to the Flight Master. --
Nurse Applewood - Warsong Hold (Borean Tundra) -- Found behind the stairs below the Zepelin landing platform, near the trainers for enchanting/tailoring. --

For Both Factions:

Olisarra the Kind - Dalaran (The capital city of Northrend) -- Found in the Magus Commerce Exchange area of the city. --

~ Politsos -- EU - Haomarush --

It took me 120 bandages to go from 350 to 410 (when it became gray).

Took me 43 bandages to get to 400 from 375.