I thought that I was going to have my first panic attack trying to take this thing off! I got stuck halfway and wasn't sure that I'd be able to pull it down to try again. The shirt is very tight under the armpits.
It does provide a lot of compression, but this is not an Elven garment with +5 Slimming magical properties. It does have +7 insulating/broil properties.

Have a friend nearby to help tickle you to death when your elbows are locked above your head and the double layer nylon is too slippery to get a hold of again.