The Bank of Canada says its new $50 and $100 polymer bank notes will last much longer than the old paper-based versions. But that added durability doesn't mean they're indestructible.

Several reports have appeared about the new bills melting, crinkling or otherwise shrivelling after exposure to very high temperatures.

On Tuesday, radio station CKFR in Kelowna, B.C., quoted a local credit union teller, Brittney Halldorson, saying staff at her credit union have seen the new bills melting in the summer heat.

"We're finding temperatures in cars, we've seen it a few times now, where three or four melt together," she told the station.

A woman in Cambridge, Ont., told the Cambridge Times last January that eight of the new $100 polymer notes shrivelled when her son put them in a tin that he placed near a heater.

So can the new polymer bills actually melt?

The Bank of Canada defends the hardiness of its new bills, pointing out that they last 2½ times longer than paper-based notes under normal conditions.

And when conditions aren't normal?

"The new polymer notes have been rigorously tested in very hot (over 100 C) and cold (under –60 C) temperatures to ensure their durability," says Bank of Canada spokeswoman Julie Girard.

"We put the notes in boiling water for over an hour and the notes retained their shape, size and properties, and could still be used as a means of payment," she says.

The bottom line? Polymer notes, like their paper counterparts, can't withstand every threat.

"The Bank of Canada cannot rule out that polymer notes may be damaged in certain extreme conditions," Girard acknowledges. Just as paper-based bills can burn, it appears that polymer notes can also be damaged by very high heat.

So if you've somehow managed to stash some polymer notes near toasters, heaters or on hot dashboards, only to return to find your cash has morphed into something that doesn't resemble currency, don't panic. You can send the whole mess to the Bank of Canada. The central bank has a claim service that examines damaged or mutilated notes and can replace the bills.

The central bank says it has processed 40 cases of damaged polymer series bills involving 197 notes since the new series first appeared last November. While this is considerably less than the 3,000 paper-based cases processed in an average year, the polymer numbers will likely rise.

So far, polymer versions of the $50 and $100 notes are the only ones in circulation. New versions of the $20, $10, and $5 notes are set to roll out by the end of 2013.

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  • The New $5 Bill

    Source: <a href="http://www.flickr.com/photos/bankofcanada/8693039417/sizes/c/in/photostream/" target="_blank">Bank Of Canada, Flickr</a>

  • The New $5 Bill

    From <a href="http://www.flickr.com/photos/bankofcanada/8694157272/in/photostream" target="_blank">Bank Of Canada, Flickr</a>: "Robotics innovation is Canada’s ongoing contribution to the international space program and demonstrates our commitment to space exploration. The Canadian-built Mobile Servicing System is the sophisticated robotics suite that helped to assemble the International Space Station in orbit. This system consists of Canadarm2, Dextre and the Mobile Base. On board the space station—a permanent orbiting research laboratory—international partners conduct scientific experiments, many of which result in an enhanced quality of life on earth. Canada’s contribution to the space program evokes pride and sparks the imagination and curiosity of our future leaders in science and technology."

  • The New $10 Bill

    Source: <a href="http://www.flickr.com/photos/bankofcanada/8693039429/sizes/c/in/photostream/" target="_blank">Bank Of Canada, Flickr</a>

  • The New $10 Bill

    From <a href="http://www.flickr.com/photos/bankofcanada/8693039423/in/photostream" target="_blank">Bank Of Canada, Flickr</a>: "The expansion of the railway in the 1880s was hailed as a remarkable feat of engineering for a young country with a varied and often treacherous terrain. At the time, the railway was the longest ever built, and its completion demonstrated Canada’s pioneering spirit by linking our eastern and western frontiers, connecting people, and facilitating the exchange of goods. Today, The Canadian train, winding its way through the Rockies showcases Canada’s natural beauty and symbolizes what we accomplished as a young nation."

  • The New $5 And $10 Bills

    Bank of Canada governor Mark Carney unveils the new polymer $5 and $10 bank notes during a press conference at the Bank of Canada in Ottawa on Tuesday, April 30, 2013.

  • The New $5 And $10 Bills

    Finance Minister Jim Flaherty unveils the new polymer $5 and $10 bank notes during a press conference at the Bank of Canada in Ottawa on Tuesday, April 30, 2013.

  • The New $10 Bill

    A new polymer $10 bank note is displayed during a press conference at the Bank of Canada in Ottawa on Tuesday, April 30, 2013.

  • Astronaut Chris Hadfield Displays The New $5 Bill

    Astronaut Chris Hadfield poses for a photo with a new polymer $5 bank note on Tuesday, April 30, 2013.

  • The New $20 Bill

    Hand holding up the new polymer Canadian $20.00 bill.

  • The New $20 Bill

    Some new polymer twenty dollar bills, which is the most widely used bank note in the country, are pictured at Montreal on November 19, 2012.

  • The New $20 Bill

    The Bank of Canada introduced the plastic see-through $20 bill on May 2, 2012.

  • The New $50 Bill

    Bank of Canada Governor Mark Carney holds a new $50 bill while standing in front of the Canadian Coast guard ship Amundsen Monday, March 26, 2012 in Quebec City. The Amundsen is displayed on the back of the new bank note made of polymer.

  • The New $100 Bill

    Bank of Canada Mark Carney shows off the bank's new circulating $100 bill, Canada's first polymer bank note, in Toronto on Monday Nov. 14, 2011.

  • The New $100 Bill

    The $100 bill was the first of Canada's paper denominations to go plastic and see-through.

  • Australia's polymer note

    An Australian 100 dollar polymer note is displayed above various international currencies. AFP PHOTO / Torsten BLACKWOOD

  • Australia's polymer note

    AFP PHOTO / Torsten BLACKWOOD

  • Mexico's polymer note

    A Mexican pesos note made out of polymer material. Alfredo Estrella/AFP/Getty Images

  • Mexico's polymer note

    Mexico City, MEXICO: A sample of the new 50 Mexican pesos' note made out of polymer material to hinder its forgery, 14 November, 2004 in Mexico City. AFP PHOTO/Alfredo ESTRELLA (Photo credit should read ALFREDO ESTRELLA/AFP/Getty Images)

  • Next: Twitter Jokes About New Bills

  • Andrew Coyne

    Even that would be better. @InklessPW: Wells designs new bills. What'll we put on the 5? Oscar Peterson. The 10? Peterson. 20? Glenn Gould

  • Cory S.

    Wait so there's no more quote from the Hockey Sweater on the new $5 bills? #manifencours

  • Tabatha Southey

    New bills should be 5 pin bowling for the $5, a Robertson screwdriver for the $10, a Canadian flag, draped over a picnic bench on the backs.

  • LauraBeaulneStuebing

    Theory about the new $5 and $10 bills: They're ugly enough that we don't want to keep them in our wallets.

  • Paul Wells

    Paul Wells designs the new bills. "What'll we put on the 5?" "Oscar Peterson." "And on the 10?" "Oscar Peterson." "20?" "Glenn Gould."

  • Wesley Fok

    Was expecting the new $5/$10 bills to literally have pictures of poop on them, based on the outcry. Surprise: they look like money!

  • Patrick Meehan

    Q: You're the federal government, what do you put on the new 5$ and 10$ bills? A: Things you've cut funding to. http://t.co/jqT3BLmENc

  • Jason Rehel

    Everyone is pretty damn hung up on the AESTHETICS of the new $5 and $10 bills in Canada. Me? I'd like money that WORKS in vending machines

  • Brittlestar

    @Cmdr_Hadfield Dude, with all the stuff you’ve had up there (guitars, Easter eggs, new $5 bills), how BIG was your suitcase?