How do I start a mercedes automatic in freezing temperatures?

modern fuel for the uk should be ok down to -30ish you do not say if you have a battery problem you could check the alternator out put should be charging at about 13-14 volts have your battery checked out it may not be holding its charge over night or buy a smart battery charger it conditions old batteries I have a opitmate 4 the dogs

Alan
January 2012