I like the heat but that might hurt. Some people I know would (my wife for one), pass out in it.
I was up every morning at dawn for couple of weeks, in August. Despite being the hottest July and August on record, I always put polypro jacket on to sit in the cockpit. About the time the sun is a few inches off the water though, I had peeled it off. It's never hot in the morning on Maine water, that is rarely above 60 degrees. Next morning I'm on the boat, I'll probably light the fireplace to take the chill off. Winters comin'