The blizzard that Sakkara casts at the beginning of the encounter is only "for the story" - he's attacking Timothy (and Alexandra, if you reach him quickly enough), and he does that by casting a blizzard over them.
Sakkara's encounter is designed to test a variety of skills and your reaction - but the initial Blizzard he casts isn't part of that. Because of this, it's not designed to kill - so if you do accidentally end up in it somehow, it'll do very little damage (compared to the actual encounter, where it does significant damage).
(But thank you for checking back with me. :3)
