Betta Fish Question about Heater,and fish?

I guess you could get a heater for it but it is not completely necessary. If you do raise the heat one degree every day until it reaches 80/82 degrees F. A 1.5 gallon tank is just fine for a betta fish. I have had a betta fish in a 2 gallon bowl for almost 5 years and its just fine, don't listen to people that tell you you need a huge tank for a betta fish.