Recommend an insulated epi-pen case
 

There are about five different forums this could have gone, but I decided on this one since it's for Miss Swede.

Looking for an epi-pen case that can hold two auto-injectors (and a few quick-dissolve benedryl packs) while maintaining a constant temperature for at least a few hours in hot/cold weather.

Since she's now in her tween years, also looking for a stylish messenger bag that perhaps also has an insulated pocket for two auto-injectors.

Many thanks in advance.

I'd look at these. http://www.frioinsulincoolingcase.com/

They are kind of boring but she might find a designer looking pouch at nickisdiapers.com. They stock Planet Wise bags which come in a bunch of design options. I'm guessing that a wipe pouch or small wet bag would be the right size to fit a case. They also have insulated lunch boxes. Use coupon code FIVE at check out for 5% off.

You might also look in etsy.com. You may find something she likes or someone who would make one to her tastes.