You may think heading indoors means you are completely safe once thunder and lightning start outside.

A building offers much better protection than staying outdoors, but being inside does not remove every lightning risk.

Lightning can enter or travel through a building in several ways, which is why what you do indoors during a thunderstorm still matters.

Can lightning strike you inside your home?

Lightning can injure someone indoors, although being inside a substantial building is one of the safest places to be during a thunderstorm.

The danger does not necessarily come from a lightning bolt directly striking a person through the roof.

Lightning can strike a building or nearby infrastructure and travel through electrical wiring, plumbing and other conductive paths.

Avoid using electrical equipment that is connected to a wall socket during a thunderstorm.

Lightning can cause a surge through electrical systems if it strikes a building, power line or nearby infrastructure.

That means you should avoid touching plugged-in computers, televisions and other electrical appliances while lightning is nearby.

Cordless and mobile phones are generally safer to use indoors as long as they are not connected to a charger.

Avoid running water

A thunderstorm may not seem like a reason to postpone your shower, but plumbing can provide another path for an electrical current.

Avoid showering, bathing, washing dishes or using taps while a thunderstorm is overhead.

This advice is particularly important where plumbing includes metal pipes or other conductive materials.

Watching a thunderstorm through the window may be tempting, but move away from windows, doors and exposed areas while lightning is nearby.

You should also avoid leaning against concrete walls or lying on concrete floors because metal reinforcement inside concrete can conduct electricity.

How long should you stay indoors?

Do not head outside as soon as the rain stops.

Lightning can remain a threat even when a storm appears to be moving away.

A widely used safety rule is to wait at least 30 minutes after hearing the last thunder before returning outdoors.

If you can hear thunder, lightning is close enough for you to take precautions.

None of this means you should avoid going indoors during a thunderstorm.

A substantial enclosed building offers far better protection than remaining outside.

Once indoors, staying away from plumbing, plugged-in electrical equipment, windows and other conductive surfaces can reduce your risk further.