I once saved Mrs. Tomassi and one of our dogs from being pulled under by a very cold, very swift Truckee river when we lived near Lake Tahoe.
It was a spring run off from a very snowy winter and one of our dogs swam across it to get at a duck on the opposite side. He made it over, but coming back he was already wet & cold and the river took him. He drifted down about a quarter mile and got to our side, but the bank was too sheer and he couldn't get up and out so Mrs. Tomassi jumps in after him! I knew she'd be next because she was wearing sweat pants and they get heavy. She managed to grab the dog (about the size of a Lab) and then grab a big root in the side of the river wall, but the current was too swift and the water was ƒucking cold. I could see she wasn't going to be able to do what she thought she could, so I went in at this point. I managed to fight the current, but that cold water made my body feel like splinters were being shoved into my legs. I knew I wouldn't be able to hold out indefinitely, so I picked the dog up and literally heaved him up over the bank. After that I picked up Mrs. Tomassi and did the same to her. I had jeans on and they were like wearing icy cement at this point, but I managed to grab the same root my wife had been holding and had enough upper body strength left to climb it hand over hand to get out.
That was some crazy sh!t. We both agreed after that, that if the dog ever did something that stupid again we'd just go to the pound and look for another dog.