There are a few different types of rugged laptops that you can get.
There are fully rugged laptops, for instance. These are known for working in harsh weather conditions and dealing with all sorts of extremes. These sorts of laptops, made with magnesium cases usually, are great for military or other in-the-field users. Average users like you and I may find them a little too expensive for our purposes.
Laptops more aligned with our purposes are considered either business rugged or semi-rugged by some. The business variety works as you might expect, handing a few extra bumps and scrapes but generally tailored specifically for indoor use. It stands to reason, obviously, that the semi-rugged laptop would be somewhere between the business and fully rugged laptop. This is where the action is.
Suppose you work in construction and need to use a laptop on the job. You may be in the elements from time to time, but you also have an office where you can park your laptop if need be. The type of unit you'd be best served getting would be a semi-rugged laptop. These usually come with indoor and outdoor screen types, too, so you can rest assured that you'll be using a versatile and highly usable unit.
In all reality, most users do fine with semi-rugged or business laptops. But in the case of first responders or military users, something more significant is needed. A magnesium-cased fully rugged laptop can run you quite a bit of money, but if you work in a rough field where access is essential you may not have a choice. Make sure you check out the Bluetooth and WiFi options, too.