What should be done to ensure the wax is at a safe temperature before application?

To ensure the wax is at a safe temperature before application, testing on the practitioner's wrist is a reliable method. The skin on the wrist is sensitive enough to give an accurate indication of the wax temperature. By applying a small amount of wax to the wrist, the practitioner can gauge whether it feels too hot or comfortable. This method is effective because it allows the practitioner to assess the wax's temperature in a way that directly relates to the client's experience without risking injury to the client.

Using a client's finger to check the temperature may not be advisable, as it places the responsibility for temperature safety on the client, who might not accurately assess the temperature. Dropping wax on the floor does not provide a meaningful assessment of safety for skin application, and mixing with a cooling agent can alter the properties of the wax, potentially affecting its performance during hair removal. Therefore, testing on the practitioner's wrist is the best practice to ensure the wax is safe for use.