Each year I go to Burningman and freeze.  This year I decided I was over the cold and would come extremely well prepared.  I searched amazon for the warmest underclothing I could find and ended up with these.  They are amazing.  In fact, they are so warm that I couldn't use them for their intended purpose, as it never got below 40 degrees on that trip.

The cut of the shirt is very good.  It is flattering and tapers in at the waist.  The shirt is long enough to hide underwear peekaboo and avoid belly showing.  When layering the neck sits even with my t-shirts. You can see I've got an undershirt on, but just slightly, and I like the look.  They hold up very well in the wash, and don't instantly burn when exposed to embers/fire.

The only thing I don't like about these shirts is they have a white and red logo.  Since I wear a lot of all black this really pops out  I wish that the logo wasn't quite so visible, but it is small, and I love the shirts enough to ignore it.  It also wouldn't make a good backpacking shirt as it is a bit bulky.  It doesn't feel like the normal silky/thin high quality thermals, but is rather a very thick fabric.

If you want to not be cold and not look like an unsexy layered parka-wearing snowman, I highly recommend this shirt.  I rarely find anything that is "too warm" but this shirt hits that level.  I love knowing it is packed in my bag and I can take on any chill with it.