Manual: Heavy Frostweave Bandage

Manual: Heavy Frostweave Bandage teaches players with 400 in First Aid how to make Heavy Frostweave Bandage.

Source
This item is a world drop from level 75 and above humanoid or undead creatures in Zul'Drak, The Storm Peaks, Sholazar Basin, Icecrown and Crystalsong Forest in Northrend, as well as level 80 dungeons and raids. To receive the drop, a player must only have a first aid skill of at least 390 (although it requires a skill of 400 to actually make the bandages). Players of any level can get the drop should they have the requisite first aid skill.