Out of the blue

Today was OK until I had to go to work at the school. All of a sudden about 10 minutes before I was due to go out the door I started to fall asleep.

I had been feeling sluggish all day but out of the blue my MS fatigue had kicked in good and proper. 

Once I went to work I sat for a while in a classroom which helped a bit then got on with my job, after I was done I sat again. Came home, shower and bed.