I do find "uhuhuh" works better too, Just didnt know how to spell it so I used the word "No" instead.
He definetly responds well to a stern voice and knows not to touch things again, Was more interested if anyone had expreienced or heard the shiver thing. Its probably a form of nervous reaction or shock as you say.
It is cute though sort of defeats the purpose telling him NO uhuhuh or whatever sternly to finish off with me laughing at his shiver.
thanks heaps.