Machines for Warehouse Environment?

Here's a doozy. We have about 10 workstation clients in our warehouse. The units only need to run the web and a middleware windows client. Problem is, I'm running into problems with dust and heat because the warehouse is filthy.

Can anyone recommend units that would work better than just off-the-shelf crappy machines and wouldn't cost an exorbitant amount?

In your shoes, I'd consider a low cost, low power (ideally fanless) terminal server client of some kind and use them with a terminal server/citrix or VDI backend.

This will hopefully reduce (though sadly, probably not entirely eliminate) overheating due to fans getting bunged up, and in the event that one does fail might reduce the impact and cost of each unit that fails.

In any case, as you know its a hostile environment perhaps it might be worth having a regular (3 or 6 month?) preventative maintenance cycle for these machines too, where they get cleaned.

Take a look at Axel terminals. I use the M70 pretty heavily in warehousing and industrial cooler environments for RDP/Citrix and terminal emulation solutions. The devices are built for the conditions and will outlast even traditional thin clients (from experience).

@RobertMoir's option is probably the most cost-effective. "Plan B" would be some ruggedized tablets or laptops (The tablet units might be more appropriate if your users need to move around the warehouse while accessing data...)

Ruggedized laptops would be a good option (though pricey). You might also consider using cheap nettop devices: they often run fanless, and could be contained away from the monitor in an enclosure that had a fan and simple filter on it.