It’s only day two after my ThermiTight procedure but my whole face is swollen

Thank you for your question and I understand your concern. Swelling after ThermiTight is quite common and some patients do experience more than others. While a compression garment can help, if it is not placed correctly, it can also make swelling worse. In addition to compression, it is very helpful to sleep with your head elevated for the first few days after treatment. My guess is that your swelling will begin to subside within the next few days. However, if you are still concerned at that time, give your doctor a call. I would rather have patients call my office with concerns than to sit at home and worry that something might be wrong. Your doctor should be able to put your concerns at rest. 

Some swelling after ThermiTIght is perfectly normal. The lymph system slows down after the procedure, which is why fluids take some time to drain. The compression garment should help control the swelling, but it is possible it is too tight or misplaced. The swelling should resolve within the next few days, but if it is not beginning to subside, please contact your provider and request a check-up. Always feel free to contact the provider who treated you when you have concerns or questions about your procedure. They should want to evaluate your issue and help you heal as quickly as possible.

I have been doing ThermiTight since 2013 and not one patient didn't get swollen. The compression garment helps to apply pressure on the cheeks during the healing but a side effect is swelling of the upper face because normal lymphatic drainage becomes sluggish from the compression and fluids back up.
If one experiences pain with the swelling, or fever and chills, they must contact their doctor immediately. However, if there ever is any uncertainty post operatively, one should always call their surgeon. I would feel I failed my patients if they went on the internet asking about potential concerns postoperatively rather than paging me!
The information provided in Dr. Shelton's answer is for educational purposes only and is not intended to constitute medical advice.  The information provided should not be relied upon as a substitute for consultations with a qualified health professional who may be familiar with your individual medical needs. If you are experiencing a medical emergency proceed to your nearest emergency room.