I recently attended an ice fishing seminar by Jack Winters and he said that if it is cold out and you lay a fish on the snow or ice it will freeze their retenas and make them go blind. I thought I would just spread the word. Be careful with those fish!
i'm thinking that you would have to leave them on the ice for awhile, and if you waited that long the fish probably would be close to death already.we always practice catch and release and have missed taking a few pics (because of a long fight or problems untangling fish) just to get em back in the water, it's all about the fish surviving and not our ego pics..
i have read several articles in the fishing mags that say laying a fish on the ice/snow is bad news. you know how ice cubes can stick to your lip some times, that is cause it freezes the miosture in you skin not deep but just on the surface. now think of how thin fish skin and eye membranes are and its easy to see the possibility for damage. also when it is well below freezing it is possible for the fish's gills to get frost bitten rather quickly, remember there whole body is not many degrees above freezing so it dont take much for small delicate parts to freeze and a fish with frozen gills is at a big disadvantage.
so if your going to release fish caught thru the ice, and you should, attleast some, do it quickly