My fire dept is located on Lake Champlain and we consider any rescue in water under 72 degrees a cold water rescue situation. I would definately attach a whistle to your pfd. Since you may be on the water after dark I would even add a strobe/flashlight combo like this. http://www.trupoint.com/product9.htm If you are going to have a dry bag onboard pack dry clothes. Of course you will have your psk so you have a way to start fire. Some of the large heat packs like hot hands would work if you can't start a fire. Pack a couple of the AMK heat sheets. Cheap and if its pouring rain a great way to make shelter. Enjoy the river.