teach them relaxation techniques...My lecturer at college said that being relaxed was worth 15% of the marks in the exam... Tension( or too much of it) just mucks up your memory.. stop revising a full 24 hours before the exam.. read through the stuff once, Not concentrating just reading lightly, and most important, READ THE QUESTIONS... sounds silly I know, but not answering what is asked is the most common mistake made under tension ie if it says "state Bloggs Law" state it in equation form or words, and identify the terms and then stop..., do NOT write an essay on Bloggs and his struggles to prove it