Applied heating pad on clothes+blanket not directly on skin yet burned my skin it was red & swollen, pain was mild.now its darker.will it leave marks?

Doctor can examine: After first-degree superficial burns, twice a day moisturizing cream helps. Such patients may find that over-the-counter hydrocortisone cream twice a day for one week, can also help. One can talk with one's primary care doctor or a dermatologist, to get some advice. Life is not so predictable. Skin darkening sometimes take months to years to fade. Some people scar more than others do.