People forget about hygiene when it comes to survival. It's just not their primary concern. However, you don’t have to get sick while you wait for help. Maintain proper sanitation just as you will when you’re not in a bad situation. You’ll eventually have to relieve yourself. There is no reason why can’t do it right. Have a roll of toilet paper or baby wipes in the passenger compartment. You can use them to clean the car or other surfaces as well.