Речь идет о рекордном полете на воздушном шаре с открытой корзиной на высоту 8-10 км. Помогите, пожалуйста, разобраться с кислородным оборудованием ('demand oxygen', one or two bits of the oxygen kit, triple system):

"I was on 'demand oxygen' and it was just too much to look at the scenery. Because it was so cold we had a few problems and one or two bits of the oxygen kit froze but that's happened before. Because of that we took a triple system - and I'm glad we did".

Буду признательна.