A competitor scrambles in the mud under barbed wire during the Tough Guy Challenge 2009 at South Perton Farm on February 1, 2009 in Wolverhampton, England. The biannual event to raise cash for charity challenges thousands of international competitors to run through a gruelling set of 21 obstacles including water, fire and tunnels after a lengthy run at the start. (Photo by Christopher Furlong/Getty Images)

After some days with temperatures below freezing point, I was out skating at some lakes at the outskirts of Oslo in Norway. After a while I noticed something on the ice. To my astonishment it was a dead frozen frog.