I am a tad concerned about my son's axolotl. Firstly, I believe we have a female. We only have one axolotl and I believe she may have reached sexual maturity as she is displaying dark marks on her fingertips. Today I noticed an opening in the tail region. It looked swollen and opened up, but nothing proceeded from the gap. Later it seemed to close. Also, she hasn't eaten since Saturday, I think, and today is Tuesday, but I believe that is because the water is too hot and I am about to do something about it. Her gills are looking more red than usual too. Would it be acceptable to add some cold water to the tank? I'd appreciate any advice.