I used to use triple section ladders to go up to the 3rd floor no problem. I wouldn't do it now.
When I was younger and stupider, I used to take what I now know to be incredible risks. In some ways, the work is more dangerous if you're not afraid of heights (like me) because you are not as careful. Fear is healthy! I genuinely cringe when I think about what I used to do.
Once, being a little bit lazy, rather than move the ladder I did the entire upper floor of a rather tall victorian house by clinging onto the window sills and brickwork. When I had gotten as far as I could, rather than clamber back to the ladder, I leaped a 7ft gap into the householder's tree and then dropped from one of the branches.
At the time I didn't even think about what I was doing. Sometimes I still see other window cleaners doing stunts worthy of a circus.
These days I am very careful when working at height, and it is very rare that I do that. I prefer to get that "in the sky" feeling by rock climbing instead, being safely harnessed up and knowing that if I fall I won't be injured.
In a few months time I'll be doing some rope access training to learn to abseil. There are some really tall skyscrapers here that I'd love to have a go at cleaning. For me, window cleaning high up in the sky is a bit of an ambition. Thankfully it is statistically a very safe way to window clean, much, much safer than using ladders.
My advice to anyone is, if you don't feel comfortable doing a window, don't do it. Usually the customer is more pleased that you're honest enough to admit that you wont be doing it. If they whine, let them. Its your health, livelihood, and indeed your life that is at risk. All they're risking is a dirty window.
Its a no-brainer.
-Philip