If you have a proper survival knife with you when the weather closes in you can make an emergency shelter; if there’s the material available to do so. But it’s better just to make sure that whenever you venture into the woods for any length of time that you have the right survival gear with you and the Sundome 2 Person backpacking tent from Coleman is that survival gear.
The Cold War era civil defense programs promoted public atomic bomb shelters, personal fallout shelters, and training for children, such as the Duck and Cover films. The Church of Jesus Christ of Latter-day Saints (LDS Church) long directed its members to store a year's worth of food for themselves and their families in preparation for such possibilities; but the current teaching advises only a three-month supply.
Your run-of-the-mill shoe stank might not pose much of a survival threat, but trench foot certainly will; baking soda is great at absorbing the moisture that might otherwise literally cause your feet to rot off your legs. As for the health of your teeth -- it will be pretty hard to get through your day's rations of homemade jerky and hardtack without some high-quality chompers. And you certainly don't want to rely on that pesky fluoride that will "kill your brain over time" (um, what?).
Earthquakes, tornadoes, and hurricanes can cause you to leave your home or even be trapped there. Roads could be blocked due to fallen trees, power lines, or even damaged earth from the natural disaster. Rescue crews can not be in all places at once. You may have to wait it out for quite a while before its over. You won't be able to go to the store or to the corner market.