REE test?

I have an REE Test coming up. And from what I've read they put a bubble over your head and you breath in it at a rested state. Well.. having a bubble over my head is not going to make me feel rested but panicy. How small is this bubble? I keep thinking of the old bubbles that divers use to use in the 30's.

I'd have a problem with the bubble over my head, too.

Can you do an RMR test instead?  From doing some quick googling, the results typically are very close, less than 10% variation.  For the RMR test, you just have to breath through a mouth tube.  And you have a plastic clip on your nose.  But no bubble.

     I had mine done at Legacy Good Sam in Portland.  They had a full sized bed in a room and had me get comfortable laying on my back.  The bubble that they use looks somewhat like what an astronaut or deep sea diver wears but it's like a half dome with the fabric stuff around all sides.  When you are laying down, they lay the half dome over your head and the fabric lays flat around it to kind of seal in your breath, but it's not really an enclosed feeling.  It's a pretty big bubble thing and you can see everything around you.  You're only in the thing for about 5 minutes or so and you basically just lay there and breath.  It really wasn't bad at all but I know I was pretty apprehensive going into it too until I actually saw what it was.     
                                                                                  Angie

Edited to add:   Picture a big huge clear plastic mixing bowl and that's what it looks like.  It is just laying there and if you panicked, you could very easily lift it off.  There's nothing attached to you, it's just kind of laying on the pillow and your chest.