In what situation is it appropriate to encourage a client to seek medical attention?

Encouraging a client to seek medical attention is appropriate when there is a visible skin condition or an adverse reaction. This ensures the client receives professional medical evaluation and treatment for any underlying issues that may not be suitable for cosmetic procedures. Such conditions could include infections, severe dermatitis, allergic reactions, or other skin disorders that require specialized care beyond the capabilities of a cosmetologist.

In contrast, the other options pertain to routine aspects of the cosmetology profession. Requests for specific hairstyles or product recommendations fall within the stylist's expertise and can typically be addressed without the need for medical intervention. Similarly, a client expressing dissatisfaction with their service does not indicate a medical issue and should be handled through customer service techniques rather than a referral for medical care. Thus, recognizing the signs of medical concerns is crucial in ensuring client safety and well-being.