Righ now, we have a normal pool of water. It is not a solid nor gas because the temperature is balanced and is causes only some movement in the atoms.
Now pretend that the water is frozen. The coldness of the water will make it into ice. The reason why ice is hard is because the atoms will stick together and will only vibrate. And that is because they lose energy
Lets take a look at the hot tub now. When water is hot, it turns into water vapor because the temperature becomes hotter which makes the atom want to spread out at a rapid pace