These little guys have been my lifesavers this summer, with all the fieldwork I’ve been doing in the hot hot sun. “Hydroflask” is the company’s name, and they make these vacuum insulated water bottles. I have put ice in them at 5 in the morning and they still have ice floating in them when I crack into them at 3 in the afternoon–after sitting in the 100° sun with me all day long. Even after the ice melts, the water stays cool for as long as I’ve ever prayed attention. And when it’s not getting quite as hot (say, when you’re visiting Montana) the ice will stay frozen over 24 hours sometimes!
There are some tradeoffs, though, to keep in mind. They are heavier than similar sized bottles from other manufacturers, and have a smaller capacity. And more expensive (these 21 oz. bottles were each around $20).
What I’ve been doing is filling up my regular liter Nalgene for the morning, and breaking open the first Hydroflask when it runs out, about the time when a regular bottle would be nice and warm. Definitely nicer to have ice water than that…
And, as the title says, this little review was completely unsolicited, and the bottles were purchased by me for me with my own money, so all you government watchmen can bugger off.