7 weeks post TT with lipo on my arms and back, and my back heats up whenever I move while sleeping. Is this normal?

Thank you for sharing your excellent question.  As you are having little other symptoms, it is probably the result of increased blood flow to the area as your body is attempting to heal from the liposuction but best to talk to your surgeon and have an in-person examination performed to rule out any issues.  Hope this helps.

Dear michellm,
this can happen in some cases after liposuction. However, without a proper assessment it would be difficult to determine what is wrong. It is best that you visit your plastic surgeon for further assessment. Only after thorough examination you can get proper recommendations and advice.
Daniel Barrett, MD

Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Thank you so much for share with us your concern. 
You must be contacting your Board Certified Plastic Surgeon for any concern or doubts that you have after your surgery, He/ She knows the way your surgery was performed and he can help you to determine what is the reason you are feeling the hot in your back, there is too many cases that cause that happens, get a physical evaluation with your surgeon as soon as you can. 
Best of Luck! 
Dr. Quiroz 

Recommend that you follow up with the board certified plastic surgeon who performed your lipo and TT.  Feeling hot after liposuction has a number of possible causes such as changes in hormone levels following the stress of surgery, nerve regeneration, more movement than normal. Recovery time can take as long as six to eight months. Kenneth Hughes, MD, ABPS Board Certified Plastic SurgeonLos Angeles, CA

As your only symptom is the area heating up and you do not have a fever or any other signs of infection, what you are experiencing is likely a part of the healing process.  However it is always best to discuss any concerns with your surgeon just to be sure.

You are probably just experiencing the nerve signals your body is sending from the inflammation caused by the liposuction you had done.  As long as you dont have fevers or chills I would not worry too much. Be sure to follow up with your surgeon.

Yes their are many changes which take place after liposuction. This may be due to nerve regeneration with sympathetic disturbances. Also hormonal changes because of stress associated with surgery can be a cause.