Other things to look for in a rugged laptop start at first sight—its outer case or chassis. Obviously, the thin plastic of many consumer models turns to shrapnel when faced with what rugged PCs go through, though it's amazing what a little reinforcement can do. Semi-rugged laptops may stick to plastic but are reinforced with tougher composite materials. Fully rugged laptops and tablets usually opt for metal.

Common chassis materials include magnesium or magnesium-aluminum alloys, with rubber or rubberized bumpers on a laptop's corners as a popular protective measure against drops. However, heftier metals like steel may still be used for reinforcement, usually as a chassis frame that acts like a roll cage for internal components.

We've already discussed doors that cover ports, but as with any laptop, you should consider which ports you need. Machines built for duty on factory floors are among the last that still have RS-232 serial ports, often used for connection to legacy data-collection equipment. SmartCard readers are common since rugged machines are usually deployed in environments where machine access needs to be controlled. Others feature modular or swappable bays for storage drives or batteries or slots for mobile-broadband SIM cards so you can go online when out in the field, away from Wi-Fi hotspots. (There's a whole nationwide network, FirstNet, reserved for first responders.)

While you can't see them easily, many rugged laptops have specially shock-mounted components. Jolt-resistant solid-state drives (SSDs) replaced relatively delicate spinning hard drives, which was a boon for the category, but some vendors go beyond that—we've even seen a heated SSD that keeps working in frigid temperatures.

Every rugged laptop has passed MIL-STD tests, and at the minimum, they're the next best thing to bulletproof. We'll refresh this guide as we review additional true-rugged systems. Meanwhile, check out the individual product summaries and detailed spec breakouts of our suggested models. Thanks for reading, and be careful out there.

Before we get into brawny machines that can survive six-foot drops and jets of water, we must acknowledge that not all mainstream notebooks are frail and fragile. Many Lenovo ThinkPads, HP EliteBooks, and other business systems are reasonably resistant to bumps and bruises, though they can't survive high dives or liquids in excess of minor keyboard spills. Even some Chromebooks carry the same designation as these hardy travelers—MIL-STD 810G, which indicates compliance with a series of tests required for the US Department of Defense to consider using a piece of equipment in a military setting. More recent models often meet the refreshed MIL-STD 810H spec.

The MIL-STD 810 standard spans over 800 pages and nearly 30 laboratory test methods for challenges ranging from weather (high and low temperatures, rain, and humidity) to physical forces (acceleration, vibration, and shock). Few computer vendors push their products over every hurdle that the standard posits, including such tortures as gunfire-recoil shock, icing or freezing rain, whether a laptop might spark an explosion in flammable gas atmospheres, and—wait for it—resistance to fungus. Rather, the manufacturer may note that the system has passed 10 or 12 MIL-STD tests.

The trouble with a MIL-STD 810G or 810H sticker on a laptop's box or vendor's website is that it doesn't tell you enough. Because no independent agency certifies MIL-STD compliance, it's up to you to look for documentation or details of which tests a product passed, who conducted the tests—the manufacturer or an outside lab—and how the tests were performed. For example, since users are prone to drop laptops, certification for shock is a popular claim. But there's no rule about what height to drop a device from.

Does this make the certification useless? Not at all. Think of it as a checklist item or the first thing to look for rather than a guarantee of bulletproof reliability, and be aware that you need to read the fine print.