And they won't work properly unless surrounded by free air.
Put a globe over them and they will overheat the ballast (electronics).
I've got four of them in globe fixtures and none of them have burned out prematurely. I went to CF bulbs about 3 years ago and I've probably replaced about 3 bulbs total from those particular fixtures in that time. The one in my stairwell is on it's original bulb, (still hanging in it's glass globe), while the other three have probably all been replaced once now.
I have used dozens in such an application, and I have never had one of them go out over 3 years now.
I, too have been using them in glass globe fixtures - one is a schoolhouse shade on the kitchen ceiling fan and another on one of those old-fashioned jelly-jar sconces. There's openings at the top for air to move in and out. The bulbs last at least a year in these fixtures.