This is actually an older story.  It just occurred to me to outline my experience with the blanket (specifically).

The blanket I used seems to be identical to the military casualty blanket.

It is a two layer blanket, blue on one side, silver mylar on the other, with a sorta-reinforced grommet in each corner.

Another reason I'm bringing up this story it that is different than what you might think.

This thing spared me in 90F+ degree weather.


What?


Yep, I used it as a sunshade.  At a minimum it saved me from heat exhaustion.

I was hydrating quite effectively with hardly any walking.  I had just arrived at Fort Jefferson/Garden Key in the Dry Tortugas (70 miles west of Key West) and set up my tent in the camping area.  From there I hauled all my ham radio gear to the North Coaling Station area (I had a permit, this was all planned).

I was wearing my boonie, heatgear shirt, super light convertible pants and, again, had plenty of water.  My thinking was that I had portable shelter from the sun.  Yeah I wouldn't get sunburn but my sweat wasn't keeping up.

I began to set up the antenna and slowly started feeling uncomfortable, eventually noticing the beginnings of a headache, despite my continual hydrating.  
(My physical conditioning was such: out of shape and thoroughly acclimated to an air-conditioned office.  I think even a daily outdoor hour long walk a couple of weeks beforehand would have been beneficial lol.)

If I start removing clothing and such I'll have to lather up in sunblock and there are no showers on Garden Key (in fact you have to bring your own water).

I decided then to put up the casualty blanket as a sunshade and take literally as long as possible underneath to hydrate in the shade.  I stripped off everything and zipped off the lower legs.   Click To View Spoiler


Here's a pic of my eventual setup: (optical illusion but the silver side IS facing up)

DryTortugas-8584 by Dan Passaro, on Flickr




The temperature difference between the top and bottom was, quite literally, profound.  If I put my hand an inch or so above the concrete I could feel a little heat radiate up.  Putting my hand SIX inches above the casualty blanket was HOT.   The closest comparison is one of those heat lamps that keep food warm.

So, YEAH, that shade under there was awesome.  Another thing I did was soak my neck gaiter and use it on my head instead.  (Anything wet on my head seems to work for me much better than a neck wrap.)


So if you want to cool something from the sun I can heartily recommend using a mylar blanket to reflect that sunlight.





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Very good post!  Smart thinking on your part.  I appreciate the tip.

Those things are pretty handy. I carry a casualty blanket with me when I go hiking/ backpacking and keep one in each vehicle for emergency use.

I've been to Ham Radio Field Day, where I have used the single-thickness Mylar blankets on the sunny side of a tent to keep things cooler. Very nice inside!

Smart move on your part, OP.