The Summit 0 and 20 have the same listed 84 × 32 inch dimensions. The meaningful documented change is synthetic fill and carried weight, not extra sleeping length.
| Manufacturer figure | Summit 0 | Summit 20 |
|---|---|---|
| Thermolite fill | 2.9 lb | 1.9 lb |
| Carry weight | 3.75 lb | 2.6 lb |
| Nominal dimensions | 84 × 32 in | 84 × 32 in |
| Named comfort/limit standard | Not supplied | Not supplied |
Aaron’s wrong order shows the tradeoff
Aaron bought the 0 accidentally and needed to vent it during high-thirties nights. The 20 has a separate owner account of comfortable use near 40 degrees with an adequate pad. These are different people and sleep systems, so they do not define a universal dividing temperature.
The 0 source and 20 source share promotional testimonials. Dustin’s clothing-assisted cold account belongs to the 20; it must not become extra independent evidence for both bags.
