I need a 40 cal/cm² arc flash suit for live work on 13.8 kV switchgear in an indoor substation. Focus on comfort and full-body protection is a plus. What brand or specific suits do you recommmend for this level of protection?

I can't recommend but do a web search, due diligence etc. Be sure it complies with either ASTM or IEC standards. See where it is made, some counterfeit PPE is out there.

Go with a well-known NFPA-70E / CAT-4 (≥40 cal/cm²) kit from a major vendor that advertises lightweight / breathable fabrics and a good hood option (lift-front or PrismShield) for comfort and full-body protection. Strong candidates are below with why I’d pick them. Try before you buy if possible — fit/mobility matters a lot for live switchgear work; many vendors/distributors will demo or exchange.

Okay, so 40 cal/cm² – that's serious business for 13.8 kV, indeed! Finding something comfy enough to actually work in is key. Indoor substation? Think claustrophobic! Speaking of heat, I once had to troubleshoot a fried control panel and felt like I was inside a toaster. It was intense, like playing Slither io but with real fire. I recommend looking at Salisbury or Oberon; they often balance protection and ergonomics well. Think about cooling systems if you are doing extended work periods too. That heat can become unbearable.