In extreme cases, the winding will get so hot that the adhesive holding the turns together and to the form material will soften and let the coil come apart or even burn through a wire or solder joint.
There are many ways in loudspeaker design to try to keep the voice coil from overheating—to try to dissipate heat. One effective method is to put the first layer of the windings on the inside of the coil. The coil form, especially if it is a polyimide film material, will act as an insulator to keep the heat generated by the coil in the windings. It will slow the dissipation of the heat on the inside of the coil. If we wind the first layer on the inside of the coil it provides much more surface area of the wire to allow the heat of the coil to escape. The heavy metal of the pole piece close to the inside of the coil is more able to help pull the heat away from the coil with the inside layer of windings exposed to it.
