Had round 2 of CoolSculpting on flanks. I experienced a "Thermal Event" on my right flank. Now there's a dark burn mark? (photo)

Very sorry to hear that you had an adverse event. First of all its very rare to have this kind of event so I am not sure if you are going to get a strong recommendation. In my practice I would recommend giving some more time and let the inflammation settle down completely -  avoid sun exposure, SPF and then re-evaluate in 4-6 weeks. Hopefully this will continue to fade. 

I recommend following up with a cosmetic dermatologist for after care and treatment for hyperpigmenatation. This can be improved with a combination of lasers, Aerolase, microneedling/prp, skin lightening, peels, and skin care. Sun protection is essential. 

This discoloration 2 weeks after a "freezer burn" is uncommon. It's probably a bit early to call it PIH (post-inflammatory hyperpigmentation). The most important thing that you can do to minimize long-term darkening of the skin is to avoid the sun and wear sunscreen. A skin care product with 4% hydroquinone like Obagi Clear or Triluma may also be used. If there is pigmentation that remains after a few months, it could be treated with a IPL or other laser or light devices.

Thanks for your question.  This is a very rare occurrence, and presents most frequently in those of darker skin types. The CoolSculpting machines have a built in mechanism that recognizes when the skin is getting too cold, and the machine shuts off. Sometimes the result is a freezer burn type of mark in the shape of the applicator.  This mark will fade over time, but that could take a few months.  In the very rare instances that this has happened here, we administer a lactic acid peel for free to the client to help lighten the pigment in the area.  Additionally, retinol creams can be very effective for at home use. It is unfortunate that you are having this experience, but hopefully your CoolSculpting results will be worth it!

This is PIH and is related to a COLD thermal event, not a hot one. This should be treated as any other PIH with Retin A, hydroquinone, and possibly lasers. A thermal event is not that uncommon and is a protective mechanism by the device to prevent a burn from being too cold. Having PIH is much rarer but it is treatable. It mostly will happen in darker skin types.

Thermal events occur when the skin in the treatment area gets too cold.  This built in "Freeze Detect" is a safety feature that prevents the skin from getting freezer burn by shutting itself off.  Sometimes the tissue in the treatment area can result in temporary blisters, redness, or brown marks (hyperpigmentation).  These side effects will usually heal themselves within several days to several weeks but in cases of hyperpigmentation the "brown marks" can take up to several months to fade.  In these cases a Retinol cream can be used on the effected skin to speed up cell turnover and help with fading.  

This is pigmentation caused by the trauma of the heat to the skin.  This should fade over time. You should contact your provider as there are treatments that will speed up the recovery time. Topical creams, light based treatments and microneedling may help. 

Hello Its very unusual to have an issue with the Coolsculpting machine they are very reliable. It looks like post inflammatory pigmentation which can be treated with a good hydroquinone cream. Just return to your treating clinic and they should be able to prescribe you the appropriate cream.