I've taken a break the past couple of days to work on a new little project, which I won't give away just yet- but the code name is "wood fired oven". At any rate, I learned something new today and consider myself wiser for it.
If you ever find yourself around concrete/cement dust and as the day progresses you notice that the sun is now shining on you where before it was only shade, make sure to put on sunscreen. But there's a catch! Make sure to first wash off any cement dust that may have accumulated on your arms, neck, and face. Then wait for the applied sunscreen to dry before resuming work.
If you choose not to, you will suffer an unholy goop that will rip out your hair as you try and scrub it away later on.
Alternative solution- wear clothing to cover up your arms and neck. And don't forget your face mask!