The fancy suits issued to Black Hat personnel did not show up on the loading dock as suits, but as rolling footlockers crammed with modular parts, so the user could configure them for different conditions. The module that was responsible for the user’s not perishing of heat stroke was branded as the Me-Frigerator. More than one type of Me-Frigerator was in the kit. One of them was optimized for conditions where direct intense sunlight was the primary threat. Which was decidedly the case in the Chihuahuan Desert on an August afternoon. It was built around a technology that had been invented and patented a hundred years ago by none other than Albert Einstein, teaming up with a future A-bomb physicist named Leo Szilard. It didn’t have moving parts, other than some valves. It was just a particular configuration of plumbing containing certain fluids. One part of it just happened to get cold when another part of it was exposed to heat. You didn’t need a motor to drive a compressor or any of that. It just worked, provided you could open the valves and make one part of it hot. And that last was pretty easy in the desert sun, especially when there were new blacker-than-black light-absorbing materials and certain other innovations that Einstein hadn’t known about. During the first century of its existence, Einstein’s invention had not seen very much practical use because it was less efficient than other ways of making things cold. But more recently, researchers had been spiffing it up with an eye to using it in developing countries where heat, in the form of sun and fire, was easier to get than reliable electricity. The manufacturers of the fancy earthsuits favored by Black Hat had piggybacked off such innovations to make these Me-Frigerator systems. Rufus dug into one of them as soon as he had good light and a functional soldering iron.