What device is typically used to determine the degree of hotness or coldness of an object?

The device commonly used to determine the degree of hotness or coldness of an object is a thermometer. Thermometers work on the principle of thermal expansion or change in electrical resistance, allowing them to provide measurements of temperature accurately. They can be filled with liquid, such as mercury or alcohol, or use electronic sensors to gauge temperature.

In contrast, the other devices are specialized instruments for different measurements; for instance, manometers measure pressure in liquids and gases, pressure gauges indicate the pressure within a system, and vacuum gauges specifically monitor low-pressure environments. None of these devices are designed to measure temperature, which is why the thermometer is the appropriate choice for determining the degree of hotness or coldness.