Gear

As they come in different 'warmth' ranges, try the lightist one.

 The design is basically the same through whole range.

 I use IceBreaker, (merino), socks all year round, different 'warmth' rates for seasons.

 My job also means a lot of walking on hard surfaces, tarmac mostly.

 I do also use the likes of Bridgedale socks, other good hiking, walking socks.

 If I want to use 'slipper' types in summer, I'd use cycling socks.

 Hope This Helps.

 Paul.

There are quite a few people who do waking socks with cushioned heels but the rest of the sock thin so not much warmth but durable and cushioned.

Merino wool in general also very good at staying comfortable over a wide temperature range.

As with Smartwool, something like this, but as noted plenty of good alternatives cf Bridgedale etc etc.

This may or maynot be of use to you Richard.
My partner works in an industrial enviorment, walking back & forth along a large machine. Many of the operators complain of foot ache at the end of each day. A few of them decided to make insoles for thier boots to hopefully reduce the fatigue.

Take a cork flooring tile as the body of your 'insole', glue a piece of cotton sheet/rag to one side and let dry - silicone sealer works, rest a telephone directory on top to make a firm stick. Draw around boot insole, cut out with stanley knife, refit 'new' cork piece into boot. Personally he says he found these to be a good insulator against, vibration, foot slap, cold and heat. I'm not saying they will be best footbed but certainly improved his quality of life for very little outlay.  

I work in a factory too, Richard, and wear merino socks all the time. More for their anti-stink properties in steel toe-cap shoes.

I only wear liner socks in stiff winter boots, as my feet can slide a bit more. The liner helps against friction, that causes blisters. I haven't worn stiff winter boots for years though.