Swimming climate

Question
I've recently taken to swimming recreationally and its working well for me.  It's getting colder and was wondering when I should stop for fear of cold-related illnesses.  Right now my hometown is in the mid-eighties most days and mid-seventies by early evening when I can make it out to the pool.  By the end of the month it will be in the low seventies during the day.  I don't mind the physical discomfort of cold water much but am wary of catching a cold, flu, sinus infection, ear infection ets...  The pool I swim in is unheated.  Thanks in advance for any advise you can provide.

Answer
Ericcc...
Well there is no temperature that you need to heed per se.  Competition temperatures range from 78-82 degrees.  I would say that if the water is around 80, that is prime.  I don't think it really has anything to do with the air temperature.  Just make sure you dry off quickly and have warm clothes after your swim.

Basically a good rule of thumb is whether you ever feel "warmed up" during the swim.  If you are swimming and don't feel like you are warm after you have raised your heart rate, then it's too cold.  You don't want to be swimming in water that doesn't allow your muscles to relax and warm up.  It's dangerous.  That type of temperature is also not going to allow your core temp to raise.  That is when it gets dangerous.

I say all this, but you can still swim in water that is in the 60's.  It's just going to be VERY cold.  I wouldn't suggest swimming in water below 76 degrees without a wetsuit.

I hope that this answers your question.
If not, let me know.