Hoarse Voice

My LO (almost 5 months old) woke up from a nap with a hoarse voice yesterday. He had a small bout of crying in my arms when I was putting him down for a nap (he is teething and has been crying more no matter what I do). He has also been wanting to nap more frequently today (1 hour after being awake) when he usually will stay awake 1.5 hours). I made an appointment with the pediatrician but it isn't until Monday. He doesn't have any other symptoms of a cold/virus or croup. The only other thing that I have noticed is that he started this screeching thing as well where it seems like he is playfully screeching, but does it often. What can I do in the meantime to help? I have the AC on, would that make it worse (it is set to 24°C/75°F)? Would a humidifier help or make it worse? Thanks!