The Scottish Fire and Rescue Service (SFRS) issued the warning as it hosts a major summit on how to tackle the threat to public safety and the economy.
British Transport Police (BTP), Police Scotland, utilities providers and Scottish Government representatives are also attending the summit in Cambuslang, South Lanarkshire, today.
In November, fires broke out in four homes in Greenock, Inverclyde, after thieves stole copper wire from an electricity substation, leaving 280 homes without power.
One family-of-four, including two young children, had to flee their home in Devon Road after thick smoke filled the property. The 28-year-old father was treated for smoke inhalation.
In a separate incident, Scottish Power Energy Networks said that an attempted theft also led to the death of the man involved near Shotts in North Lanarkshire.
SFRS assistant chief officer Lewis Ramsay said: "Anyone engaged in metal theft is risking lives. These are not victimless crimes and we are working closely with police and others to protect our communities.
"Thieves' interference with power infrastructure has caused surges of electricity resulting in fires breaking out and flames and toxic smoke taking hold within homes.
"We have also seen cases where high-rise buildings have been left at severe risk due to thieves vandalising fixed equipment needed to get water to firefighters tackling a blaze.
"It isn't hard to imagine the terrible consequences of a fire within a block where there is significant delay getting water to our crews.
"Those involved in metal theft must know their actions put the public at risk as well as the firefighters and our fellow emergency responders who are called to emergencies."
Justice Secretary Kenny MacAskill, who is attending the summit, said that the Scottish Government is committed to cracking down on metal theft and is proposing measures to tighten up the licensing of metal dealers.
He said: "Along with proposals for tougher legislation, more effective enforcement has been introduced including the British Transport Police team dedicated to tackling metal theft.
"The Crown Office and Procurator Fiscal Service has also adopted a tougher prosecution policy in relation to this issue and courts now reflect the full consequential costs from an offence."
BTP said that it has seen cable and metal thefts fall by 50% in the last year but is not complacent about the problem.
Chief superintendent Ellie Bird, divisional commander for BTP (Scotland), said: "These crimes not only cause immense inconvenience and upset to the public but they can also put them in real danger, and those who are foolish enough to commit the crime.
"As the divisional commander for Scotland I am comforted that the force has established a dedicated team who have become crucial in ensuring damage, theft or disruption to major infrastructure projects is avoided.
"Our officers are now embedded in the Borders Railway and Edinburgh to Glasgow Improvement Project, and working closely with a range of partners to mitigate any threat from thieves.
"Today's metal theft summit brings together a wide range of organisations determined to tackle the issue."