Each plastic surgeon has their own guidelines. Typically I allow my patients to have a cool compress applied for 10 minutes on 10 minutes off. Do ask your plastic surgeon.
Your plastic surgeon will always be your best resource when it comes to specific postoperative care instruction/advice. Generally speaking, patients need to be VERY careful about the direct application of ice (or heat) over surgical sites. These areas may be insensate (numb); cold or heat injuries may result without the patient even being aware… If you do decide to utilize ice, do not apply directly ( place it over a towel) and use it for short periods of time. Best wishes.