A man in Halifax told the Toronto Star that when he left the money on a toaster, it curled up like a Coke bottle. The paper also talked to a man who placed a stack of eight $100 bills in a tin can near a heater, only to find they had shriveled up.
However, the Bank of Canada is not buying it.
"The bank has encountered no evidence that polymer bank notes are being affected by heat as has been suggested in recent news reports," the bank wrote in an email to the Los Angeles Times. "Bank notes printed on polymer material have been used in many countries for years, most of which have climates far hotter than Canada."
Malancha Gupta, who teaches chemical engineering at USC, agreed that tales of the notes melting seemed unlikely. "The melting point of polypropelene -- the material the notes are made of -- is in the range of 130 to 175 degrees Celsius [about 265 to 340 degrees Fahrenheit] and should be able to withstand high temperatures you would experience in everyday life," she said.
Canada introduced polymer currency last November, starting with the $100 bill. A $50 plastic bill was introduced last spring, and a $20 bill is coming by the end of this year. Plastic $10 and $5 bills are to be in circulation by late 2013.
The polymer notes are more expensive to produce than the previous paper bank notes, but the Bank of Canada says the plastic money will last 2.5 times longer. The plastic bills are also recyclable.
But the real impetus to move to the polymer bills was to make Canadian currency more difficult to counterfeit.
The new bills are tricked out with all kinds of security measures that include certain areas where the ink is raised, special transparent windows with specific images etched in them, and numbers that appear if you hold the bill up to the light -- some of which are reversed for extra security.