Stop outdoor activity immediately and seek shelter in buildings. If there is no shelter available, your best protection is a cave or ditch. Do not take laundry off the clothesline. Get out of water and off small boats. Stay off the telephone during the storm.
Lightning can cause serious injury or even death.
Nearly 100 Americans are killed by lightning each year. Persons struck by lightning receive electrical shock and most likely will be burned. If CPR can be administered, it can be used to revive the person hit by lightning. Many of us have experienced a thunderstorm and lightning, but a severe thunderstorm means that the winds reach more than 57 miles per hour, or there is hail inches or more in diameter. Once you see the skies darkening, the storm is approaching and it is time to get indoors immediately.