Yesterday I awoke to find a hummingbird I've been feeding for a few years hanging lifeless by his tongue from the feeder. I removed him from the feeder, cupping him in my hands, thinking he was dead, and felt his little heart beat...then he began shivering. Over the hour he warmed, took some nectar while I held him, then decided he wanted to perch. He perched on my hand/arm and preened. He eventually was fly and took a few rounds in my LR, landed, let me pick him up, and when I opened the back door, he flew off. I was relieved when he came back to the feeder throughout the day and again this morning. To keep the feeders from freezing, lights on them will do a lot to help, and I'm also trying a reptile heating pad.