I have only had snails in tanks with no heaters before, but I'm thinking I would like to have a couple in my betta tank. Would the heated water be okay for them or should they be in cool water only?

What type of snails have you got Fishrpets? Apple snails?

If so, they love warmer temperatures.

The following is an extract from www.applesnail.net

"The optimal water temperature for apple snails lays between 18 to 28°C (65-82°F). As with many cold-blooded animals, apple snails are more active at higher temperatures. At higher temperatures, they eat faster, creep faster and they grow faster. Also higher temperatures mainly induce the reproduction of the apple snail. At lower temperatures (18°C/65°F) the apple snail enters a dormancy state in which they creep away in the mud and become very inactive. Temperatures below 18°C/65°F should be avoided as the mortality rate quickly increases."

I keep alot of mine in Trop-like temps.Keeping them in higher temps does shorten their lifespan though.I look at it this way though-Do I want to watch a snail in semi-hibernation just laying in the bottom of my tank,or would I rather see them sliming around,eating,and checking things out?
I really enjoy them being active so I opt for the higher temps.Hopefully it doesn't shorten their life-span too much.I know that it's alot more fun to watch them interacting with the tank.

Thanks y'all. I did put a couple in the betta tank. They didn't move for a while and I was afraid I had just made escargot But they are happy and on the move now!
Oh yeah, they are apple snails. I got gold and brown ones.

The lady at the shop said do you want the yellow or blue? I said where are your blues, I don't see any. She said they call these brown ones blue for some reason. I just shook my head and went on. I've had blues, purples, magentas, well a mixture of them when I had the snail only tank and it's been long enough that I had forgotten some things, but not long enough to forget how to see colors!

I think I may have been thinking there was a problem with the shortened life spans...that sounds familiar now. But I agree, as long as they are fine and happy(and I didn't cook them ) that's all that matters.

Warm temps are fine, but as stated about it does shorten their life span. I don't think it is a drastic shortening, but since they are growing faster and their metabolism is faster it will make a difference. Make sure they have a source of calcium to prevent shell erosion. Some Bettas will also nip at the tentacles, so if you see that happening watch out. I have kept apples with Bettas before and it has been fine. It just depends on the fish. I have had goldies play volleyball with a golden apple snail before, so...