Frigid Armor

Acquisition
Skill trainers Hero skill trainers Signet of Capture
 * Nightfall
 * Baram (The Kodash Bazaar)
 * Nightfall
 * Warden of Whispers (Chantry of Secrets)
 * Prophecies
 * Melikos (The Black Curtain, only after completing Prophecies or Eye of the North)
 * Eye of the North
 * Lord Glacius the Eternal (Bjora Marches)
 * Whiteout (Jaga Moraine)

Trivia

 * Although this is an Elementalist skill, the character portrayed in the skill icon is a Warrior.