Peppermint essential oil is one of those oils that you do no want to leave home without. Keep it on hand for those pesky headaches or to help with discomforting indigestion. It is also a useful oil in the event of fever, nausea, and vomiting. And don't forget about its energizing properties. When you're feeling particularly tired or fatigued, it'll provide just the pick-me-up you need!