I believe the temperature of a "psiball" or energy ball depends on what type of energy you are putting into it, and what it is you want it to do. If I form a ball to be a shield and it is hot out or I am dealing with fire. I am using the energy to protect me therefor the air inside the ball will be cooler than the air that is not inside the ball. The opposite of that is also true.
what the energy magick coven think and what i personally belive is that the psi ball energy is based from your minds energy which you have to put into your psi ball with the tempurture you want eg. if you want a hot psi ball you have to think of something that is hot and transfer that thought from your mind and fuse it with the energy and trafer it through your body into the psi ball.