Question about water

[GyGbeetle]

All my enclosures have a water dish, and I use the filtered water that comes out of the fridge. But it comes out really cold, and last night our Burm was sitting in the cold water, and she was swaying back and forth. It was odd to witness and it freaked me out. Of note there was a cat sitting next to her enclosure too. But when my husband picked her up, she was like ice, so we warmed her back up in a bath and she was fine.

My question is, can I safely use tap water for the snakes? What does everyone else use for the water in their snake's enclosure? We haven't put any water back in. She's a very active snake as soon as the sun goes down; their is no doubt she is nocturnal. She tries to get out of her enclosure, and will sit in the water dish trying to get out.

Sorry if this seems like a dumb question