Ready.gov tells us our main concerns should be fresh water, food, clean air, and warmth. They recommend these basic supplies for an emergency kit:

• Water, one gallon of water per person per day for at least three days, for drinking and sanitation
• Food, at least a three-day supply of non-perishable food
• Battery-powered or hand crank radio and a NOAA Weather Radio with tone alert and extra batteries for both
• Flashlight and extra batteries
• First aid kit
• Whistle to signal for help
• Dust mask, to help filter contaminated air and plastic sheeting and duct tape to shelter-in-place
• Moist towelettes, garbage bags and plastic ties for personal sanitation
• Wrench or pliers to turn off utilities
• Can opener for food (if kit contains canned food)
• Local maps

They go on to suggest extras that might be relevant based on situation, but I’m still thinking about what are the most important basics for any disaster or emergency situation.

These items make a basic, no-frills emergency kit.