In my job as a legal secretary, I worked a lot of overtime -- 7 days a week especially immediately before and during trial, and often into the wee hours of the morning. I can't say long hours were THE cause of my eventual cardiac arrest, but they did work hand-in-hand with other bad health habits. I didn't eat right, not enough sleep, no exercise. Developed hypertension, high cholesterol, diabetes and I was way overweight. The arrest was bound to happen sooner or later. The body just can't take that much work.
To some degree, I admire the slackers of this younger generation. They don't want to work that hard and many of them don't. In my day, I didn't really have much choice. There were other secretaries who could have helped, but many of them were married and had children. Since I was single, it was assumed, unlike the married secretaries, I had no life, so I was always available to work. And unlike my colleagues, I learned how to do things the other secretaries couldn't or wouldn't learn. Instead of compelling the others to learn these things, the bosses found it easier to just see good old Applewood and have her do it. My generation, unlike the present one, wouldn't dare say no to a boss.
A few days before my heart gave out, I was asked to electronically file a court document because a secretary didn't know how. I told the secretary, in her boss' presence, that she really should learn how to electronically file herself because someday I might get hit by a bus and then what would she do? The secretary and her boss just laughed. I was told later that while I was laid up in the coronary ICU, that same boss wanted to get in touch with me to have me walk his secretary through an electronic filing. Fortunately, ICUs don't have patient phones. Not sure what he and the secretary did, but it wasn't my problem.
We may think we are indispensable and irreplaceable, but trust me -- we aren't. It's more important to take care of ourselves. The employer will be around long after we are gone.