Gloves. If you get cement on your skin wash it off quickly.
Unfortunately cement, when added to water, generates calcium and sodium hydroxide in solution making the pH very high (around 11). At this pH it degrades skin effectively dissolving it. However as the nerve cells dont tend to respond quickly to high pH burns it creeps up on you so you don't notice it. Additionally there is an abrasive quality to it especially when sand is added which makes it worse.
There are specialist barrier creams that help but gloves are really the only way to deal with exposure.
There is a secondary issue in that cement contains chrome 6 although in very small quantities these days. This can cause what looks like an allergic reaction. Once you are sensitised you will break out in a rash every time. In high sensitivity cases this can be quite serious ( the film Erin Brockowitz is all about chrome 6 although that was in the drinking water so slightly different)
To give some context to how important gloves are ihad a ground worker freind who was working on a concrete slab. Some concrete got inside his welly and stayed there most of the day until he finished. The cement had left a lovely round hole in his skin which got infected. He had to have his foot removed just above his ankle.... its serious stuff so treat it with respect.
