You can leave the batteries in this one, even if you’re using alkalines. When not using the Divide+, you can rotate the battery compartment to separate the batteries from the contact terminals so they won’t corrode in storage. There’s also a foldaway wire handle so you can hang it on a carabiner or a hook.

If you want to save batteries or just prefer hanging out by gentle flickering candlelight, keep a spare emergency candle or two. The Coghlan’s 36-Hour Survival Candle ($10) has three wicks that’ll last for 12 hours each. Keep a lighter or some matches nearby.

A Water Purifier

Most of the time, your water supply will work even when the power goes out. But major natural disasters can knock it out or damage it, and you might get dirty water. The Grayl Ultralight Compact Purifier Bottle ($70) is a solid and fast one-person filter that’ll last 300 uses—a total of 40 gallons—before you need to swap the filter. It’s what I trust when traveling to countries with no guarantee of water sanitation.

Another option is the Katadyn Steripen Adventurer ($110), which purifies using ultraviolet light. Dunk it in your water and stir. It won’t filter out sediment, but it’s small, lightweight, and runs on replaceable CR123 batteries. You can also try Katadyn Micropur tablets ($16). They’re cheap and easy to store. Drop them in water and wait briefly. The taste isn’t great, but no water-treatment tablets or droplets are, in my experience.

Another option is LifeStraw’s Personal Water Filter ($16)—just sip out of it like any regular straw and it’ll filter out 99.99 percent of waterborne bacteria for up to 1,000 gallons of water. If you have a large household, you may prefer something like the MSR AutoFlow XL Gravity Filter ($110). Gravity filters take longer to purify water. You can boil water, but it won’t filter out sediment, and boiling uses fuel and takes time.

An Air Purifier

Wildfires are becoming an annual hazard, especially on the West Coast of the US, and they can spread dangerous amounts of particulate throughout the air. Homes aren’t very airtight at all. Keep that toxic, carcinogenic junk out of your indoor air (and out of your lungs) by purchasing an air purifier for your home. The Coway Airmega 200M ($197) is my favorite affordable model for an average-size room. Check out our Best Air Purifiers guide for more recommendations from the WIRED Gear Team.

You probably already have some face masks at home, but if you don’t and you live in a region susceptible to wildfires, you should pick up a box of disposable, medical-grade masks so that you can breathe easier if the air becomes saturated with smoke. Fortunately, the best masks that protect against Covid-19 also protect well against smoke. We recommend the Kimberly-Clark N95 50-Pack ($47) and the Opecticid KN95 60-Pack ($14). If these are out of stock, as many masks frequently are, check out our Best Disposable Face Masks guide.

A Propane Camp Stove

Safety note: Don’t use any of these stoves indoors. All of these fuels give off potentially deadly fumes that can accumulate and kill.