From the other side of the "kids on the job" issue. I started going with my dad when I was 8. I didn't feed chippers or run chainsaws. I watched, fetched water, drug a little brush and raked. At 8 I had sense enough to stay out of the way and I had actually learned to do as I was told (seemingly a foreign concept to many kids(and parents). I didn't run a chainsaw until I was in my late teens. Likewise with climbing (I climbed sooner but not in customer's trees). At 39 it is kind of nice to honestly say"over 30 years of experience" but I don't since people can't believe it. Still I think the early experience was great-for me, maybe not every or even most kids.