Yours truly is now among the elite few, the chosen ones, the proud select. I had to get up on the roof of my house and shovel snow.
Before you nominate me for the 2004 Darwinism Awards, let me explain...
Four inch ice damns have accumulated in the gutters due to near-record snowfalls, and the various exhaust and vent pipes protruding through the roof cause localized melting, which then backs up under the shingles and runs down the inside of the walls then across interior floor joists before dripping to the floor below. Water on structural wood is bad, very bad.</rain man>
My technique for avoiding a nasy slip and fall is to first shovel the 4' drift from the patio deck so the ladder has solid footing, then while on the roof always keep my center of gravity low and at least one foot braced against the bottom of one of the most solid vent pipes. If I ever have to do this again, I may well rig me up a safety harnass tethered over to some permanent structural fixture like a tree or my truck in the driveway. (taking dangerous chances)-- (calculated, ameliorated risks when necessary)++
I may experiment with outdoor-approved electrical heat tape in the vicinity of the varied and sundry vent/exhaust pipes. This would provide a channel through/across the ice damn, to allow meltwater drainage out instead of back-in-and-under.
But don't cry to me if you try this and fall to your death or break your neck and are permanently paralyzed for the remainder of your bleak, miserable, haunted, takes-a-nurse-to-wipe-your-arse-for-you existance. Or electrocute yourself and spouse and chilluns and the paper boy and all your beloved housepets plus the nest of mice in your attic. You've been warned!