Onion. Use a slice of raw onion to treat splinters, wasp bites, and blisters. The onion's anti-inflammatory properties draws deeply embedded splinters to the skin's surface, making them easier to remove. Onion, like vinegar, will also counteract the alkaline in wasp venom. Apply a slice of raw onion directly to wasp bite.

Vinegar has been used over the ages to treat everything from rashes to stings, bruises, sunburn and heat exhaustion. Make a paste of apple cider vinegar and baking soda to calm and soothe the skin from bee stings, poison oak or poison ivy. Mix lavender and apple cider vinegar to treat sunburn. Mix a teaspoon of apple cider vinegar into water to replace electrolytes and combat heat exhaustion like sports drinks do. Straight vinegar will counteract the alkaline in a wasp bite. Press it against the skin in a cold compress to heal bruises.