While to shooting in rather cold-weather (-14C), the ball-head on my tripod became very stiff and very hard to move. Even with the knobs at their minimum which normally cause the whole thing to drop completely, I had to apply force. Yes, I was partially frozen but two cameras (both freezeproof) I had with me kept working without any issues. The third one (not freezeproof) would no longer focus.
The question is what causes the ball-head to become so stiff?
More importantly, can anything be done about it?
Also, are there models which do not have that problem?