RE: [John Muir Trail] Heat and Shade
- Definitely consider taking the chrome dome if you're susceptible to sun/heat issues. I've use mine backpacking in the So. Cal. sun to keep cool. I hate hats with big brims and hats with attached neck flaps. I'll often wet my minimal baseball type hat and wrap a wet bandana around my neck or place it under my hat to help cool down. That helps but nothing beats a chrome dome umbrella. And I would argue that an umbrella is the best piece of rain gear to have. I wish I had mine on the JMT last year when we had 8 days or so of afternoon monsoonal rain. Weight? Yes, a consideration but if you use it for rain protections and eliminate heavy head gear you might end up saving weight.
High wind can cause problems and if you're using hiking poles it can be difficult to figure out how to attach your umbrella to your pack. EuroSCHIMR makes a hands free system but is heavier. http://www.euroschirm.com/trekking.php?session=4GifP7oKDLBU8&sprache_land=usa
As an added bonus a chrome dome will protect you from those nasty martian brain washing rays. Two umbrellas will do an even better job.