Talk:Frost/@comment-114.79.29.170-20151117094801/@comment-159.118.178.86-20151217082424

The damage that it takes during the invulnerability period is made extra health for the frost shield.

When you cast another shield in the same spot after the invulnerability period it also gains the extra health from the invulnerability period of the first cast of the frost shield.

So in practice what you do is watch your shields health and the second it starts to go down you recast it in the same spot.