Chelonia refers to turtles. "Chill" refers to what happens in winter in Vermont; not the chill we humans experience, we're talking about Chelonian style hibernation.
The Chelonian chill can last six months in Vermont. It takes place in the bottom of lakes, ponds and other bodies of water. That’s where the 39 degree Fahrenheit water, the densest water, settles in, like the turtles, for the winter. It’s a good temperature for turtles to chill in.
Spiny Softshell Turtle
Instead of forty beats per minute like on a warm summer day, during hibernation the Chelonian heart drops to one beat every ten minutes.
The Chelonian Chill seems a bit risky since a good portion of it may take place under ice. There’s no going to the surface to fill the lungs with oxygen. Turtles can get all the oxygen they need through two areas of their bodies. They open their mouths and let water into their throats, which are lined with tiny blood vessels that absorb oxygen from the water. Cool? Yes. Meanwhile, at the other end of the ‘business’, they can do the same through their cloaca, their anus, their bums. Cool? Yes, but maybe a little less so for some folks.
There’s still more amazing turtle stuff going on under the ice: going with insufficient oxygen can lead to a buildup of lactic acid, which can be fatal, similar to what over-exerting athletes can experience. Turtles resolve the lactic acid buildup by dissolving small amounts of calcium salts from their shells, which neutralizes the lactic acid. Of course, turtles avoid much of a buildup of lactic acid by doing just about nothing through the winter. That’s chillin.