Ben Kane on Broad Peak 8051m, -20°C
In 2012 Ben was guiding on Broad Peak, 8051m high and the 12th highest mountain on earth. He had a Hispar 500 sleeping bag to use as his inner bag inside the Hispar Overbag, but he found that using both was actually too warm!
The Overbag came in useful anyway when he used it as his only bag on the summit push (with his Xero down suit inside).
"As for the sleeping bags, I was blown away at how well the Hispar Overbag works. I used it with my Hispar 500 above base camp and it was simply too warm, but great to have just in case."
Technical Note: Overbags like the Hispar Overbag are so warm when used over another bag that the inside bag can be very light. In fact in most cases on a big peak it will probably be better not to take two bags, but to use just one Wide bag (all Hispar bags have a Wide option) as the only sleeping bag and to boost the performance with warmer clothing inside as you go higher, as Ben found out.