How do I cope when physical trade work is wearing my body down?

You can fix any turbine, hundreds of feet in the air, and your body is sending the bill for it, the climbs, the cold, the years of hard use. That is the honest cost of demanding physical work, and feeling it is not weakness. It is your body telling you the truth about what the job takes. Listen to it now, not later. Your body is the one tool you cannot replace, so tend it like the valuable thing it is. Stretch, rest, treat the small pains before they become large ones. There is no pride in grinding yourself down until you cannot climb at all. The wise worker protects the instrument he works with. It is also fair to think ahead. This work may not be one you can do at full strength forever, and that is not defeat, it is reality. Your knowledge is worth as much as your climbing. In time you might train others, take on work that spares your body, or pass on what you know. Honor what your body gave to this trade by caring for what remains of it.