Mountain High EDS O2 system battery

"In future if I go above FL180 I will have a spare battery and a
battery
inside my clothing (32C degrees is about optimum battery operation body
temp
is 36C) with wires and connectors coming out to connect to the EDS
unit.
I will also carry a spare or emergency oxygen system.
As simply having the battery in the pocket of the glider exposes the
battery
to the cold temperatures so its just as useless.
Think of another thing its freezing cold you take your hands out of the

gloves you then have to fumble with the battery and fly the glider."

Point(s) well made.

So far my O2 experience has been up to FL180. Certainly going far above
that brings forth other serious considerations. I have thought I would
install a continuous flow system as a back-up to the EDS if, and when I
decide to fly at those altitudes. Then also a spare/emergency?

Do you have any special considerations for the glider primary batteries
when it gets that cold?