Your head is worth protecting. Any time there are people working overhead, you should be wearing head protection. You don’t want to catch a shackle or a C-wrench on the cranium dropped from a catwalk or the steel without a good helmet. Any head protection is better than none, but there are certain types of helmets for certain jobs. How do you know which helmet is the right one for the job?
If you’re an electrician, then you should use a helmet that will protect you against the hazard of shock and arc flash. Climbing helmets are often vented, but those vents that make them more comfortable in hot weather make you vulnerable to arc flash. In the event of an arc flash, should you be in the arc flash zone, then those vents could allow your to get second-degree burns on your scalp.
Helmets are classified according to national an international standards, and those designed for electricians should be class E or class G according to ANSI/ISEA Z89.1 and CSA Z94.1. A class G provides dielectric protection for up to 2,200 volts and a class E up to 20,000 volts. For the type of work that you and I typically do, a class G is fine.
I just got a new Petzl Vertex Best for $115 with free shipping on Amazon. It’s complaint with ANSI/ISEA Z89.1-2009 type 1 class E. Type 1 means that it is designed to withstand impact from above, but not from the side. I don’t often find myself in environments where I need head protection with class E compliance, but now I’m prepared just in case.