At some parts of the Boise River the temperature is 44 degrees.
The three-day swift water rescue seminar, which started Sunday, is being taught by a master.
Nate Ostis of Mcall has shown the finer points of swift water rescue to firefighters and national park rangers all over the country.
"Really what we're working on is an active avalanche," said Ostis. "It's a mountain falling down right in front of us. It may seem benign, but the power of water is deceptive. What I'm trying to sell people on is how quickly things can go out of control."
In this drill, crews practice grabbing a probably hypothermic victim from the current.
The trick -- and it's a critical one -- is to not drown along with the person you're trying to save.
It's not a coincidence this training is going on right now. After all the temperatures are going up, school's out, and you know kids will want to get in the river and that could be a recipe for trouble."