To cold to go swimming

Answer 1

It all depends on what you are doing in the water. For instance if you are just going to wade around your body will not produce a lot of heat and you will cool off way faster then if you were moving around. If you plan on exercising the lowest I'd do it in is 66*f anything below that and you will start facing some serious issues really quickly. If you are just wading around not doing anything I'd say keep it above 72 even though you can go lower you might get uncomfortable.

This isn't taken from a scientific report or anything, but this is just my personal experiences from swimming over the years.