Complex sentence: Italian casualties were 1,247 killed or missing and 2,361 wounded and there were more than 2,000 frostbite cases from combat in the subzero temperatures of the French Alps.
Split into simpler sentences: Italian casualties were 1,247 killed or missing and 2,361 wounded. Additionally, there were more than 2,000 cases of frostbite from combat in the subzero temperatures of the French Alps.