Strange things happen when you get in the water when you shouldn't. Who dives in freezing water and what would they be doing there?
For one thing the water is so cold that cold blooded fish don't move too fast...
For instance you may be able to catch a fish by hand... here is Jean Jacques handling a sturgeon!
We have it on video.
How cold does the water have to be... ?
Well if you have to dodge ice floats it may be cold enough.
This is a walleye shot that day. We were still on the winter fishing calendar.