Ultra-ultralight sleep system for summer heat

At home at 70F, I sleep under a light cover, so at 60F, I definitely want something over/under me.

In the Grand Canyon on stupid-long “day” hikes, I’ve leaned against a rock and taken a nap for a few hours.  Of course going up or down a few thousand feet and choosing surfaces that were or weren’t in the sun all day, you can pick your micro climate.

Think about radiant effects on any clear night.  Getting under a tree or tarp can feel 10F warmer and greatly reducing condensation.

And don’t be in the lowest-lying area – cold air pools low and being 20-feet higher on a slight knoll can be 15F warmer.

It sounds as if continuing global warming will affect where we choose to backpack and when to go there.  As of last August, the temps above 9000′ in the Rawah and Never Summer wilderness areas in northern Colorado remained cool, dropping at night of course.  But in July, I was informed by the USFS that the rains were so intense, they were calling it their “monsoon season.”  And in the previous year, 2020, there were fires in Rawah that closed large areas.  In visiting Colorado, have noticed that the fires have been present during the last several years.

I think we have to take it year by year and call ahead to the USFS before finalizing trip plans.  The postings on the USFS sites are OK and well intentioned; but not always up to date.