If you lose power during a storm or an earthquake, you may be able to get by for three hours, but do you have what it takes to stay connected if the lights go out for three days -- or longer?
Floridians are scrambling to prepare for the worst as Irma -- one of the most powerful hurricanes ever recorded -- barrels through the Caribbean, causing widespread destruction.
And it's not over yet -- hurricanes Jose and Katia lurk nearby, with Jose in the mid-Atlantic and Katia in the Gulf of Mexico.
In today's smartphone-dependent world, those in the path of a storm can't count on apps to be a sole source for all news and communication with the outside.
I grew up in South Florida, where planning to go for a week without power is part of the norm for summer hurricane season.
In 1992, my family huddled around the radio and battery-powered TV for information after Hurricane Andrew leveled entire neighborhoods nearby.