Relief for Relief Teachers
I just discovered that subs overseas are called "relief teachers." To see if things were the same over there for these angels of mercy, (well you need them, right?), I looked around a bit for posts about them. Yup. They need the same support as subs here in the U.S.
Here is a thorough article, written for subs....er....relief teachers. It is thorough. As a teacher who needs subs, you might find it helpful as well. (Please don't ignore your subs' needs. It is a tough job.)
Read the article here: Relief for Relief Teachers