Location Flash Kits in Extreme Cold

[evonzz]

While strictly not a landscape question, i have a location question.....

I am planning to travel far north China next month to shoot portraits.
The temperatures are expected to be a high of around -15 deg C and down to -30 deg C.
I would like to shoot with a bron mobil kit + Ring Flash, however i am not sure the kit will cope so well in such extreme cold.

I would expect the battery cell to run down quickly in the absence of any warming device and perhaps it is simply too cold to use it.  My other concern was the flash tube. i would anticipate the glass could become very brittle and be susceptible to cracking.

I would appreciate any feedback or comments about using flash in extreme cold and snow.

Thanks
Rodney