In addition to flashlights, candles and a radio, your stash of emergency supplies should include a helmet.

That advice comes from the Centers for Disease Control and Prevention (CDC), which points out that head injuries are common causes of death during tornadoes.

"We understand that people who have seen the tragedy that tornadoes can impose are looking for any useful and effective ways to protect themselves," said the CDC, which doesn't, at present, have any research to demonstrate the effectiveness of helmet use to prevent head injuries during a tornado.

Still, the suggestion makes sense. It also couldn't hurt -- unless the helmet is not within easy reach.

"Because the time to react may be very short, people who choose to use helmets should know where they are and have them readily accessible. Looking for a helmet in the few seconds before a tornado hits may delay you getting safely to shelter," warns the CDC.

And of course, helmets should not be considered an alternative to appropriate shelter.

"Rather, helmets should be considered just one part of their overall home tornado preparedness kit to avoid any delay."

For more information on how to prepare for natural disasters, including tornadoes, to to: www.emergency.cdc.gov/disasters/tornadoes/during.asp.