Everyone knows that when a thunderstorm hits, it’s best to take refuge inside your home. However, what you likely don’t know is that  lightning can still shock you inside your house if it strikes and sends electricity through the pipes and water.

John Jensenius, a lightning safety specialist for the National Weather Service (NWS), just spoke out to warn people that in order to stay safe in their homes during a storm, they should stay away from anything that conducts electricity, which includes both wires and the plumbing.

“Certainly showers would be dangerous, it would be dangerous to be washing your hands or washing dishes,” Jensenius said. “Just avoid those any time you can hear thunder.”

It should be noted that impurities in tap water conduct electricity, plastic pipes won’t protect you from these dangers.

“Water can conduct electricity as well,” Jensenius said. “We see that on the outside where lightning strikes something and if there are puddles around, it can easily electrocute somebody nearby the puddle.”

The way a home is grounded can change how badly a lightning strike could affect your plumbing.

“When a house is built, it should be built so that when your electricity comes in, it’s grounded to your house,” AccuWeather Senior Meteorologist Dan Kottlowski explained. “If your house is grounded to separate rods that are basically stuck down into the ground, then that’s a bit safer because nothing is attached to the plumbing.”

You can contact an electrician to find out if your house’s electrical system is grounded to the plumbing system or not.