The spur wax embedder is best used at room temperature so that the wax is more malleable allowing the wire to be pressed into the wax. If it is too cold, i.e. during winter, the wax is more brittle and could crack under pressure from embedding the wire in this way.
This is an easy way to embed your wax foundation into your frames.
Simply insert your wax foundation sheet in the frame appropriately and rest it on a board or plank of wood so that the wires are on top and have a hard surface to press into the wax. Run the spur along the wire carefully with some pressure. Do not press too hard as this will cause the wire to cut through the wax. Instead apply enough pressure to get the wire firmly embedded into the wax.