In a sense, yes, as long as you realise that temperature measures heat, not cold, and the Celsius scale is just a range from 0 to 100 where those temperatures were originally defined to correspond to the freezing and boiling point of water at atmospheric pressure, respectively (actually it is now defined a little differently, but it isn't important to this discussion).
0o Celsius is an absolute temperature of 273.15 Kelvin (absolute zero, or 0 Kelvin is as cold as it can possibly be, the temperature at which atoms do not move at all). So really, your question should be rephrased as "can it be half as warm as 0o C or 273.15 K?", to which the answer is yes, it could be 136.575 K or -136.575o C.
In a sense, yes, as long as you realise that temperature measures heat, not cold, and the Celsius scale is just a range from 0 to 100 where those temperatures were originally defined to correspond to the freezing and boiling point of water at atmospheric pressure, respectively (actually it is now defined a little differently, but it isn't important to this discussion).
0o Celsius is an absolute temperature of 273.15 Kelvin (absolute zero, or 0 Kelvin is as cold as it can possibly be, the temperature at which atoms do not move at all). So really, your question should be rephrased as "can it be half as warm as 0o C or 273.15 K?", to which the answer is yes, it could be 136.575 K or -136.575o C.
I doubt if you have survived until today (at the above suggested temperature), so maybe any further contributions won't reach you?
If you think 0'C is cold, then your normal temperature is something like 5'C or 10'C. Then, it will make sense that twice as cold will be - 5'C or -10'C respectively.
My reply was towards Michael who speculated that the questioner lived in a cold environment where 0 C is common. In the contrary: he might never have encountered a value less than 10C
Cold is subjective and is not proportional to temperature even on an absolute scale (e.g. Kelvin.) There are formulae to calculate windchill, and they could be used to calculate cold assuming there is no wind. The North America and the UK formula is given here: https://en.wikipedia.org/wiki/Wind_chill#North_American_and_United_Kingdom_wind_chill_index
and for Aussies a more realistic formula that includes humidity is given here: https://en.wikipedia.org/wiki/Wind_chill#Australian_Apparent_Temperature
Using the UK formula, with a wind speed of 0 km/s then the apparent temperature at 0C is Cold = Twc = 13.2 C. For it to be twice as cold Twc = 6.6 C.
putting Twc =.6.6 back into the formula with wind speed still equal to 0 gives:
Perhaps you should direct your question to the people living in Siberia? They consider -20C (without wind) as a pretty nice and warm weather, I'm told.