How can i make my pup stop....

Being too sticky when i need to do something while i'm on my knees, or sitting on the floor?

Couple of days ago my water heater was shot, and we had a huge leak in our yard, the flame was still going and i went out to put it out so the boiler wouldn't overheat and go boom..

So when i was on my knees trying to reach for the control Apollo would stick his nose were my hands were...and when he realised it was boring he would use me as a bench, and he started to lie on me.... i pushed him once because i didn't want him to push me into the flame, and that got him going! splashing the water all over me (i admit that was funny) but i got soaking wet from his zoomie..

What i would like to know.. is how can i let the dog know when he can come near, and when he can come closer... sounds like a sit and wait would work, but since that is what i did and curiosity won over the obedience (OH WHAT IS DADY DOING THERE!?).. i think there should be other way..
I don't want to tether the dog.. i would feel that i'm going around the problem and not trying to solve it in a positive way.