I've recently joined the Canadian Rangers, which is a reserve military presence in various isolated and remote communities throughout Canada. We're primarily involved in such things as remote military training exercises (wilderness survival and first aid), search and rescue, and volunteer dog-sled trail maintenance. As such, I had the opportunity to take an ice-rescue training course, and jumped at the chance! It was a weekend course; Friday we spent the day clearing a hole in the ice (it was 3 feet thick) so a bit of a task!, Saturday was theory and classroom learning, and Sunday was fun times in the water!
The temperature Sunday morning was -35*C so I wasn't extremely excited about hopping in the water, but the sun started shining and it warmed up enough to make for a fantastic day. I did a few rescues with the drysuit on which was toasty warm, but I also couldnt resist getting in for a 'proper' swim! I chickened out at the last minute and put my wetsuit on, but I spent 10 minutes or so doing little laps of the 15 foot hole. Then I was 'rescued' twice and put in a hypothermia burrito; which is a few sleeping bags and a silver heat-retaining body bag on top a layer of foam. I 'm thinking it helped to prevent any afterdrop and I warmed up quite nicely! I think I might employ a similar strategy after my early April swims, where I tend to get pretty uncomfortable afterdrop symptoms.
Here is a link to a video of the exercise: https://www.youtube.com/watch?v=3V-K7E0YNrQ&feature=share