i agree its just damage once, and one temp neg level.
however;
16hp damage takes out more than just the 2nd lvl people. it takes out nearly every animal (not the high Con ones), anyone with less than 14 con is pretty much toast, at least everyone one who didnt make it out of the radius in the first couple rounds. anyone unprotected from the weather in the first few minutes is taking 1d6 + 1d4 every minute... thats 26 points of damage in the first minute (3 years dnd time) 16 + 5 (neg lvl) + 1d6 + 1d4 (non lethal)
all outside movement is screwed, @4 squares of movement to enter a heavy snow square is pretty harsh, visiblity is screwd also. so that tomorrow when the wights rise, they are going to have cover initially, and once they are adjacent to you, neither of you is running away. not to mention high winds is keeping everyone outside prone.
our brave party
Hector Paladin of Torm 4th lvl paladin
george 'the scoundrel' 3rd lvl rouge
albert the wizard 5th lvl wizard
caelic the pious 2nd lvl cleric
Cookie the cook / henchmen 5th lvl expert
round 1: ouch, wtf, is everyone ok? the lvl 2 cleric died? and the lvl5 wizard? and the 3rd lvl rogue? fuuuuuu. ok, you crawl over here. have ideas for saving those guys from being actually dead? me either, no worries (sorry fellas, roll up yetis that would be awesome)
round 2: its damn cold, we need to move and find shelter, whats with all this snow, lets move two squares north back towards the cave we cleared out two days ago. ya i know its going to have a pissed off bear in it. it looks like were going to be better off crawling the whole way, instead of getting knocked over every 10 feet. this snow shit is getting old fast.
round 11 (110feet later) hector and cookie take 5 more damage (avg), hey, share that damn lay on hands before i die over here! what do you mean your spell for the day is create water!
300 yards later, as a small troop of yeti emerge from the woods, make spot checks to see your corpse.