Milky white susbance from beak

My 10 year old African Grey parrot began to have a milky white drip from his beak this morning...he wouldn't talk or move around...but after about an hour he began to act normal, talking etc. I put him in an outside aviary during the day, but I change the food and water before I put him...could it be too hot for him outside? It's very hot here this summer (Georgia) The only avian vets are in Atlanta, and I live 50 miles away, I'm a senior citizen and I have cancer and can't drive so I have no way to get there. Could you tell me what to do? I don't know wat to do wihtout my Henry...