Cooking burn on right arm is now surrounded by large red, warm-to-the touch, patch of skin. does this signify an infection and what is to be done about it?

Burn: Did you just burn it or has it been awhile since the burn. It isn't uncommon to have red, warm skin right after the burn takes place. If it isn't a fresh burn and there is redness, swelling, tenderness, warmth, swollen lymph nodes, or red streaking - those can be signs of infection. Consider a telemedicine or virtual health eval with your doctor to get a better idea.