Wierd thing that only happens at church?

A couple months ago I was at church and all of the sudden I got really hot, and short of breath. Next my arms felt weightless, but my hands and elbows seemed extremely heavy. I was a little off balance at this point when my vision seemed to darken and blur around the edges, until only the focal point of my view was visable in color. Then I left the building to get some fresh air. This happened again today, but I left before it got too bad. This has happened 3 times, and each time I had been at church for at least 1/2 hour.What is happening and why does it only occurs at church?