I've seen construction workers equipped with overalls working on warm days, there is a tendency to drop the top half and tie the arms around the waist. Could be entanglement hazards? But then I suppose if it was a hot day a jacket would not be worn at all? Personally I'd reckon that if particular clothing was required for H&S reasons (including Hi-viz flashes) it might be seen as sensible to offer a range to suit different conditions, including light tops (tea shirts) and that only supplying one type might not be a good idea. If on the other hand, it's about brand and saving money rather than H&S then I'd not let them make the decision a H&S issue?

I would go for seperates myself. The boiler suit type may not 'fit' everyone and there may be bursting issues either under the arms or other areas. With the boiler suit type they will need to wear something under it too

John I am guessing that Hi vis flashes means something like the silvery retroreflective scotchbrite material. On its own this does not provide hi visability if not on a conspicuous colour like yellow/orange etc. Just a point to consider as my teams wanted to go for boiler suits with same and I said nope it ain't hi vis. We had a lot of site traffic inside and out so they needed to wear hi vis conspicuous in daylight and in headlights. Hope that is of use to you. Kind regards Jeff