The breath attack of the cryohydra was 21d6, and I made the mistake of allowing WizarDru to use my d6's, which seem to roll high. The result: 83 damage, 41 with a DC 18 Reflex save. Ouch.
Both of us made our saves, but 41 put Bellsin in the negatives, and put Astrid at +14 HP or so. Gah...