"Uh, ice is cheaper than gasoline."
If you have ice. This was a trick used by tank crews and other motorized crews in the Western Desert during WWII. They did not have ice. Besides, enough gas to soak a washcloth (all you need) isn't going to cost as much as a bag of ice. Most folks probably spill more filling their lawn mower.
Now an old man, I have ice and gasoline, and I take them both when I go fishing.
But, thanks for the tip nevertheless.