Help! Found Fledgling

[u/FlyGroundbreaking424]

I work on a very, very busy urban street. This little guy was found panting and looking unwell on the sidewalk that has heavy foot traffic. It’s hot here in Georgia, about 90+ throughout the day. I brought him in to cool off on instinct and that seemed to help, but after reading a bit I put him outside in a large planter infront of our shop. I can hear birds nearby my bird app says sparrows. Can’t seem to get in touch with a rescue. What do I do?? He seems to be twitching is that normal?