An environmental test chamber is about the closest an engineer can get to being a god, without being a member of the Everything2 power structure. These enormous contraptions are designed to test equipment under a wide variety of different weather conditions.
The capabilities of these devices vary. Wide ranges of temperature and humidity are common features. Integrated vibration tables are also useful for testing equipment that needs to survive a rough drive or an earthquake. Some specialty chambers are made to handle thermal shock, altitude simulation, high pressure environments, dust sprays, or precipitation simulation.
Test chambers of all sizes are available. Bench-top models sit on one's desk. Reach-in chambers range in size from dorm fridge to industrial freezer and can be mounted on wheels. Permanently installed walk-in and even drive-in sizes exist for testing weather effects on vehicles and other large equipment. No matter the size, the chamber will be totally sealed, probably with heavy doors and insulation. It may have pass-through connections (USB, serial, and parallel) if it's intended to be used for testing equipment that needs to connected to a computer. A humidity chamber will require a water hookup, and heating chambers may require a natural gas line.
Modern test chambers can be remotely programmed and monitored if they are connected to a network. In person programming is done on the front panel, or on a fancy touch-screen unit that your vendor will no doubt try to sell you.
North American manufacturers of test chambers are numerous. If you want to buy one as an accessory to your home, see a therapist. If that doesn't help, you can look up vendors at http://www.etcdirectory.com/.