Lights will go out across the planet Saturday night as the world marks the fourth annual Earth Hour.
The event, aimed at raising environmental awareness, will run from 8:30 p.m. to 9:30 p.m.
Many Ottawans are planning on taking part.
"If everyone pitches in for one hour to turn off lights, we can save a lot of energy and that'll just help the Earth," said Erin Chapman.
The Westin Ottawa will be holding an Earth Hour celebration, where guests will be shown how to make grilled cheese sandwiches by using a candle to heat the pan.
Earth Hour began in Sydney, Australia in 2007.
