A hot plate is a small electric device used in cooking and sometimes in science experiments. The origin of the device is unclear, but most reports suggest it was invented in the first half of the 20th century, when small electronics became available. Hot plates are inexpensive and are often a staple of hotel and college dorm rooms.
The mechanics of hot plates are quite simple. The device is usually powered by an electric plug, which when plugged into a socket, heats coils within the hot plate much like an electric burner in a stove. Some newer models feature halogen heating, which heats much quicker than the traditional methods.
The plate material is generally a heavy metal, such as cast iron, or ceramic. The rest of the hot plate may be steel or plastic. Most hot plates have one or two burners and a variety of knobs for temperature settings and heat warnings.
In small apartments or studios, hot plates can be an alternative to a large stove. Many furnished single apartments come equipped with a hot plate, and will not allow a stove to be installed. Although some college dormitories prohibit the use of hot plates because of fire risk, many students keep them regardless, as a means for reheating coffee or making hot snacks.
Inexpensive motels have long provided hot plates to guests, although many now substitute microwaves. In America, certain mid-20th century nostalgia surrounds the use of the device, with many associating it with long vacations and cheap inns. One recent American travel memoir, written by a college professor in 2007, is even titled Cheap Motels and a Hot Plate: An Economist's Travelogue.
Scientists use hot plates in replacement of a live flame heat source, such as a Bunsen burner. In 1942, a New Jersey man named Arthur Rosinger filed a patent for a magnetic stirrer for use with a hot plate. The stirrer operates by placing a plastic-coated magnet in the heating vessel, while having a rotating base magnet below the vessel. This self-stirring technology is frequently used in chemical experiments.
Hot plates are a fire danger, and have resulted in many fires and even fatalities worldwide. These fires can be caused by overheating the plate by accidentally leaving it on, or occasionally by having the cooking item catch fire. Never leave a hot plate unattended, and be sure to keep a fire extinguisher with you in case of disaster. Experts recommend that children not be allowed to operate hot plates without adult supervision.
The heating devices weigh about six to eight lbs (2.7-3.6 kg,) depending on the materials used. They vary in price, with single-burner models available from as low as $15 US Dollars (USD) to up to $400 USD for an advanced inductive heat version. Some newer models look like trays or griddles, allowing a larger heating surface usable for multiple items. Similar to the hot plate is the warming tray, which has a lower temperature range and are often used by caterers to keep food items at the correct temperature.