Yesterday we went to Trinity Hot Springs at Featherville, Idaho. It's a beautiful natural pool where we could enjoy full mask snorkeling and had our son practice using it. We could see where the hot spring was coming out of the ground. It was snowing outside but it was very cozy in the water. The children loved practicing swimming in it. In the dome tent was the source of hotter water. We could only stay in there shortly, it was hot. The rest of the pool temperature was very cozy ranging from 93F to 98F. Our daughter wasn't submerging her head under water and you can see her hair partly frozen at times. Outside temperature was in the low 30's F.