That is way way too cold for red eyes at night. I would get some heat on it and make sure it stays around 75 degrees Fahrenheit (23.88 degrees C according to a converter) at night. I use a ceramic heat emitter with a thermostat and it works very well.

The noise likely means you have a male, he could be looking for amorous activity but it's not necessary to get another if you're not interested in breeding. If you do get another...females are typically bigger than males and do not call. You would need to quarantine the new frog for a minimum of 30 days to make sure it is healthy before introducing her to the frog you already have.