That means your vehicle won't work. Your walkie talkies won't work. You get the picture.
To protect your electronic devices you need a Faraday cage. But you can also make one. Here are some suggestions for a homemade Faraday cage
1. Buy a metal garbage can and store the devices in it. It should protect from the EMP surge.
2. Line a shopping bag or backpack with multiple layers of aluminum foil.