Standard Thermostat
A standard thermostat controls the heating and cooling systems within a home. It must be manually adjusted as needed.
In the past, standard thermostats had mercury in them, which is toxic if it escapes into the environment. If you are getting a new one, make sure it's mercury-free (most new ones should be anyway!). If you are taking out an old one, open the front cover to check if it has a little drop of mercury in a glass bulb inside. If it has mercury, bring it to a local hazardous waste depot for proper recycling and disposal.
A standard thermostat is simple and easy to turn down to save energy when you don't need the heat.
The first thermostat appeared almost 400 years ago (in 1620), when Dutch inventor, Cornelis Drebbel fabricated a mercury thermostat to help regulate the temperature of his chicken incubator.