Betta fish-cold water?!

I just got a betta fish today, and since its summer, I keep my air conditioner on, almost 24/7.The water in his tank is a little cold to the touch. But I cant tell if its too cold or not..he seems to be doing fine, It doesnt seem like he's sick or...

anything. But I read that the temperature has to be around 80.Its deifnitely not that warm.I dont want to spend all kinds of money on a heater-his bowl is only a 3/4 gallon betta bowl.

Do you think he'll die, or do you think he'll be alright?

maybe make it a little warmer and I'm sure he'll be fine just remember to feed him and everything.. I've had betta fish before..

beta's are very hardy
you can completely abandon your fish for two months and it still wont die
as long as you clean the tank once a month
and feed him every other day he should be fine

even if the water is 80 it will feel cold to the touch. If you think it is to cold go to the pet store and buy a thermometer that cost four dollars and place it in the tank then you will always know how warm or cold the water is