- Mix 2 oz of orange Gatorade (refrigerated) and 2 oz of tap water.
- Place in a 6 oz (or larger) plastic bottle with a lid.
- Agitate constantly at an ambient temperature of 15°F or less for 40 minutes or more.
Admittedly, if the weather is cold enough for your Gatorade to freeze in the bottle on your hydration belt while you're taking a run, it might be too cold for you to appreciate the slushy you made.
This was at the weekend. I ran this morning (without carrying any liquid) when the temperature was right around 0°F. They don't allow the kids to go outside at recess at these temperatures, but with my extra layer of fleece (trousers/pants, top and gloves) on top of my normal winter running gear, I actually was a bit warmer than I needed to be. The only issue I had was when my head and therefore my hat got a bit sweaty, I ended up with a block of ice pressed against my ear!