Stress can be really harmful in the classroom. Meditation is a great resource to deal with this problem, plus it can be used as an English teaching resource as well specially when teaching topics like "The body".
This practice can have the double effect of calming both students and teachers before a lesson which is being foreseen as "difficult".
It can become part of the routine our it can simply pop up from the teacher's sleeve when the time is right.
Enjoy, and relax...
Got the video from this page: http://news.health.com/2015/10/12/7-everyday-habits-that-improve-mood-according-to-science/?xid=bustle