Sure fire is a way to start a fire in bad conditions or when a hiker has no man-made equipment, like when the fuel is wet, or the lighter has run out of fuel. Some hikers will carry tinder in a few forms, such as a few cotton balls soaked in pure petroleum jelly, fat wood (pitch). Alcohol-wipes and alcohol-hand-sanitizers are other options. Vegetable oils, and some fruit oils, like olive oil, coconut oil, corn chips, or nuts are edible and can be used to help start a fire because of the oil in them. "Bad" conditions also includes high altitude because of less oxygen, high winds blowing out a fire, high humidity that soaks either the fuel source or the igniter.