Iowans are probably more concerned with staying cool in this week’s sweltering heat, but they’re also being reminded about the dangers of another force of nature. Today marks the start of Lightning Awareness Week.

National Weather Service Meteorologist Jeff Johnson says lightning is more dangerous than most people think. "Lightning is an underrated killer," Johnson said. "It’s actually killed more people nationally each year than tornadoes."

People struck by lightning often suffer a variety of long-term, debilitating injuries. Johnson says lightning bolts have killed a couple of Iowans in recent years.

"Nationally, so far this year, we’ve lost 15 people," Johnson said. Most of the deaths from lightning strikes occur between the months of June and August. Last year, lightning was blamed for 28 deaths in the U.S. Even when it appears a thunderstorm is far away, Johnson says it’s never a good idea to be outdoors.

"Basically, anytime you’re in or near a thunderstorm, you’re at risk – up to and including 15 miles away from the rain core," Johnson said. "Most of the lightning fatalities actually (involve) people not receiving rainfall at the time they get hit."

Find out more about lightening safety here .