What should be done if a client experiences a chemical burn during a treatment?

Rinsing the area with cool water is the most appropriate response if a client experiences a chemical burn during a treatment. This method is crucial because it helps to cool the burn, reduces the heat and irritation associated with the chemical, and dilutes any remaining chemical agent on the skin. By cooling the area, you can help prevent further damage to the skin and alleviate the discomfort experienced by the client.

In the context of the other options, applying warm compresses would not be suitable as heat can exacerbate the burn, increasing pain and potential tissue damage. Applying antiseptic ointment could interfere with the healing process if the chemical is still present on the skin or if the burn is severe, necessitating professional medical evaluation. Continuing the treatment is never advisable, as it can worsen the injury and compromise the health and safety of the client. Therefore, rinsing the area with cool water stands out as the necessary immediate action in the case of a chemical burn.