Defending champions Borussia Dortmund are looking to turn up the heat on German league leaders Bayern Munich when they take on Nuremberg on Friday even though arctic temperatures are forecasted. Dortmund are second in the Bundesliga, but level on 40 points with both leaders Bayern Munich and third-placed Schalke and Borussia have the chance to steal a march on their rivals. A win at Nuremberg would see Dortmund go top and put the pressure on Bayern to win at Hamburg, whose coach Thorsten Fink has said his team will have to \'scratch, bite and fight\' if they want to beat Munich. A cold front is sweeping across northern Europe and the temperature is expected to be between minus 10 and 12 degrees in the Nuremberg stadium come kick-off on Friday night. The German Football Federation (DFB) has said postponed games are not expected as all Bundesliga clubs have under-soil heating. The thermometer dipped to -13 in Dortmund\'s 1-0 win over Freiburg in December 2009, but Borussia\'s brand of attacking football is running hot and has caught the eye recently. Japan winger Shinji Kagawa scored twice in their 3-1 win over Hoffenheim last weekend, a week after Dortmund hammered Hamburg 5-1 in the Hanseatic city to put the pressure on Bayern. \"Dortmund are the yardstick at the moment, they have already put together two spectacular performances, for me they will be the champions this summer,\" said Nuremberg coach Dieter Hecking. Bayern head north to battling Hamburg On Saturday night, Bayern have their work cut out at Hamburg, who showed plenty of courage to come away from Hertha Berlin with a 2-1 victory last Saturday, having been hammered by Dortmund the week before. \"We will not raise the white flag or throw in the towel,\" said Fink, whose team have lost just once in 10 games since he took charge. Fink, 44 and who won four titles as a player at Bayern, took over as Hamburg coach in October after an eye-catching spell with Swiss side FC Basel, but says there will be no love lost against his old club. \"We battle for our points and we will keep our foot on the gas, that is the only thing I want to see from my team. We need to scratch, bite and fight.