On the 17th December 1937 the Republican Army captured the town of Teruel. Aware that the Nationalist Army would counter-attack, the 15th International Brigades were moved from Madrid to a salient on the 3,500 ft high Sierra Palomera overlooking Teruel. The soldiers had trouble with the weather with temperatures dropping to -20C at night. However, they were able to withstand continuous air attacks made by the Condor Legion and the Nationalists eventually abandoned the attempt to take Teruel by frontal assault.
http://www.spartacus.schoolnet.co.uk/SPteruel.htm
