Toronto's fire chief is warning the public about a surge in fires involving lithium-ion batteries after crews dealt with two battery-related fires within 24 hours this week. Chief Jim Jessop told CBC Radio's Metro Morning a two-alarm fire that broke out in an Etobicoke high-rise building Wednesday morning "absolutely had lithium-ion batteries involved." To date, crews have dealt with 51 fires related to lithium-ion batteries, said Jessop. Battery fires 'greatest' public safety risk, chief saysJessop said fires involving lithium-ion batteries can be more intense, and they also produce more hazardous smoke for crews to deal with. Jessop said the guidance firefighters now get when entering buildings, especially high-rise units, is to assume they will be dealing with lithium-ion batteries.