The Ten Essentials according to the book Mountaineering: The Freedom of the Hills (which also makes a great gift) are: Navigation. Topographic map and assorted maps in waterproof container plus a magnetic compass, optional altimeter or GPS receiver. Sun protection. Sunglasses, sunscreen for lips and skin, hat, clothing for sun protection. Insulation. Jacket, hat, gloves, rain shell, and thermal underwear. Illumination. Headlamp, flashlight, batteries. LED bulb is preferred to extend battery life. First-aid supplies, plus insect repellent. Fire. Butane lighter, matches in waterproof container. Repair kit and tools. Knives, multi-tool, scissors, pliers, screwdriver, trowel/shovel, duct tape, cable ties. Nutrition. Add extra food for one additional day (for emergency). Dry food is preferred to save weight and usually needs water. Hydration. Add extra 2 liters of water for one additional day (for emergency). Emergency shelter. Tarp, bivouac sack, space blanket, plastic tube tent, jumbo trash bags, insulated sleeping pad.