If you'll excuse the pun folks - chill out a little please?
My understanding, for what it's worth is that application of carb heat cannot cause carburettor icing. Do be able to do so, you would need to have moisture content already in the air. If it's there in moisture form then you are already in danger of carb icing and it's not the application of carb heat that causes it.
If it is too cold for moisture in the atmosphere, and it ain't too cold for you to be there in the first place without freezing your hands to the control column, then application of carb ice will raise the carburettor temperature well above about 10 degC.