My implants are hard after putting a heating pad on them - is this dangerous?

From the symptoms you describe a visit to your surgeon is warranted. An evaluation is needed to diagnose what may be causing the hard feel of the implants.

Dear Exquisite436404,
I understand your concern. However, without a proper assessment, it would be difficult to determine what went wrong. It is best that you visit your plastic surgeon for further assessment or ask for a second opinion. Only after a 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

First, you did not cook your implants, or you would have burned yourself first. If your implants are hard, please be checked by your plastic surgeon. Things can be tried now to help soften your implants. If you have little tissue, your implants may feel hard since you are mainly feeling your implants only, especially if they are saline.

Go back and see your surgeon.
They should be able to advise you properly.
If you are still concerned, seek an opinion from a member of the British Association of Aesthetic Plastic Surgeons.

Hi and welcome to our forum!Application of external heat to a healing wound will increase tissue vascularity and predispose to bleeding, which may have been the initial source of the firmness. This converts to fibrosis, or scarring around the implant. You may be a candidate for capsulotomy or capsulectomy to release the implant from scar.Revisit your plastic surgeon for evaluation, examination, and discussion.Best wishes...