Keep a change of clothes in your car for those unexpected changes in weather, an unexpected change in travel or to get out of wet clothes.

On one assignment I was in Rocky Mountain National Park working on a story about Grand Lake and the western entrance to the park. I got a flat tire just before sunset and wasn't comfortable driving home on Trail Ridge Road at 12,000 feet in the dark on a doughnut tire so I found a hotel room in Grand Lake. The problem was I didn't even have a toothbrush or a change of clothes with me.

Since that day I keep a bag in my car with a change of socks (again for those endless hikes where my shoes get wet), an entire outfit of warmer and dry clothes (sweatshirt, t-shirt, pants, hat, gloves, baseball cap), a light down jacket, and essential toiletries (toothbrush, toothpaste, hair brush, deodorant).

Surprisingly I use the supplies in that bag pretty regularly. Just remember to restock it with anything you might take out to use.