When I looked it up this is what I found. Personally I have not had to try any of these. Please let us all know if any of these work for you and good luck to you!
Tip #1: To remove a scorch mark from linen or white cotton fabric, dip a piece of old fabric in hydrogen peroxide, lay it on the scorched portion of the fabric, and rub with a hot iron (not too hot). If it doesn't work the first time, repeat until the stain is completely removed.
Tip #2: If you scorch cotton fabric while ironing, plunge into cold water immediately and let stand 24 hours. The scorched areas will disappear.
Tip #3: To remove scorch mark from a garment, take a clean, soft cloth moistened with white vinegar and rub over discolored area. Take another clean cloth dampened with water and rub area again. Continue pressing or ironing garment.
Tip #4: To remove a scorch mark from clothing, rub the mark with a lemon and set garment out in the sun.