Ok, you've got completely the wrong idea. You do not want shorts and polo shirts if you are going to be outside for long periods of time in 110º weather. You will burn to a crisp. Also, don't bother with undershirts, the extra layer will make you too hot.

Short of going full Middle Eastern style and wearing a thawb you will want regular fit linen trousers, regular fit lightweight shirts (linen, linen/cotton and light cotton weaves). The important point here is that you need clothing that is loose on the body, allowing air to circulate, yet covers as much of the body as possible to protect from the sun, which is the real enemy. On that note you really should cover your head and the back of your neck at all times, as you will almost certainly pass out from heat stroke at some point if you don't. So you will need some kind of hat with a full brim (slouch hat, giggle hat, panama hat, etc).

As for shoes, there really aren't any good answers here. Sandals are a must but an unacclimatised white person can't wear them all day long without getting sunburn on their feet, which REALLY sucks. I'd still recommend a pair for days when you won't be in the sun for long stretches of time though. Lightweight leather dress shoes (full calfskin, blake construction) that can be worn sockless are also bearable in high heat. If you're working outside, boots that are appropriate for the job but as light as possible are your best bet. Suede desert boots would be my choice, unless you're working in construction (in which case get a recommendation from the site foreman). All socks are hell in hot weather so you're probably best going for thin cotton socks that you find provide the most comfort when on your feet in boots for hours. Your feet are going to sweat and overheat in boots whatever you do, so focus on alleviating problems like wear points and staving off blisters.

Finally odds are you will sweat almost nonstop so you will not be able to re-wear shirts and, to a lesser extent, trousers. Make sure you have at least one shirt for every day between washes plus a couple of spares and enough pairs of pants to get by. If you're working five or six days a week then I'd say between 7 and 10 shirts and between 3 and 5 pairs of trousers. A pair or two of shorts and a couple of t-shirts for lounging around at home are also a good idea, but you won't need as many of those as you won't be able to wear them outdoors for very long.

On a tangent, if your work permits it try to adopt a different daily work pattern. Start early, around 5AM or 6AM, and work through until about 11AM. Take a siesta in shade or indoors through the high sun period and then resume work around 3PM, working through until your hours are up. If you can do that it will make a huge difference to your quality of life.

Finally, don't forget your sunscreen. SPF 30+ at all times.

TL;DR - Slip, Slop, Slap.