The United States experiences more power outages than any other developed country in the world. As a journalist and author who has written extensively on climate survival and preparedness, I try to look beyond effects to try and understand the causes.

Extreme weather has caused power outages to increase fivefold in the United States over the past 20 years. Today, more than 100 power outages per year can be linked to weather events. That’s up from single digits two decades ago.

Storms have become more intense. From hurricanes in Puerto Rico causing the largest and longest blackout in US history, to wildfire threats in northern California forcing power shutdowns, the ramifications of nature’s wrath regularly push millions of people into darkness each year. In fact, about one in four US adults has experienced a blackout lasting longer than 12 hours. So, what can we do?

First and foremost, preparing yourself is key to health and safety when an extreme event hits. A recent posting on Goal Zero explains how you can keep yourself and your loved ones safe by creating an emergency plan. Portable power stations, solar generator kits, rechargeable lanterns, and power banks are all great devices to have on hand and to use as part of that plan. And there is good cause for using battery and solar powered devices: more than 10,000 fires per year are caused by people burning candles—and many people burn candles when the lights go out. According to The National Fire Protection Association, “Candles used for light in the absence of electrical power appear to pose a particular risk of fatal fire.”

Other risks also arise, of course, when the power gets cut. Heat-related deaths and deaths among patients on electricity dependent medical treatment, such as ventilators and dialysis machines, can also be pegged to power outages. There are millions of electricity dependent individuals in the US. For example, more than 2.5 million Medicare beneficiaries rely on electricity for medical devices. Older adults, above the age of 65, are most susceptible to heat illness and without power there is no air conditioning to cool indoor temperatures. There are nearly 50 million people in that age bracket in the country, so the number of people at risk when the power goes out isn’t small.

Along with sage and sometimes simple advice on what to do when there’s a blackout, it’s also important to remember what NOT to do. For instance, avoid flammable lighting sources, don’t plug all electrical items in after a power outage to prevent a surge, and don’t remain inside if you smell gas—evacuate immediately. (For more steps, go to ready.gov.)

To be sure, there are lots of resources to help deal with the effects, or symptoms, of power outages. It’s trickier to address causes: emergencies aren’t so predictable — which is why emergency preparedness is important. Meanwhile, a good understanding of what can cause a disaster or emergency in your area is a smart approach to safeguarding from the unexpected.