You can determine if something has become colder by feeling its surface temperature with your hand or a thermometer, noting a decrease compared to a previous measurement. Additionally, you might observe condensation forming on the surface, which indicates a drop in temperature below the dew point. Changes in the state of matter, such as freezing of liquids, can also signal that an object has cooled.
Depends on what energy you are "sucking". If you suck out potential energy, your something will be closer to the center of gravity in the area. If you suck out heat energy, it will become colder. If you suck out matter-energy(nuclear energy) your something will become iron. If you suck out life-energy, you will become depressed or a vampire.
colder
Something that is cold can become hotter by gaining thermal energy from a heat source. When heat is transferred to the colder object, its molecules start to move faster, which raises its temperature. This process is known as heat transfer.
This reaction is called an exothermic reaction. It releases heat to the surroundings as the products lose energy and become colder.
awake or energetic
This surface become colder.
when something is cold it is at a low temperature but when something is icy it is covered with ice.
Your skin is one of the easiest way to tell of a temperature shift, a thermometer, mist coming from your mouth when you exhale, frozen hands with no gloves, and if you become cold easily.
It depends. If the river is in the mountains or near the Poles than it's probably colder but if the ocean is like the arctic ocean or something like that then that's probably colder
A brown/black dwarf.
Marble is colder than room temperature
This surface become colder.