Soldering error with wire
If it is in a coil then the answer is possibly. If the cross sectional area has been reduced then 'yes'. If you just burned the insulation on the outside then 'no'. See if you can zoom in on it with a camera, microscope or magnifying glass. Will it hurt? That depends on your application. If you can, clip off the burnt end and try again. You may want to use a lower temperature on your iron. Also make sure the burned end that may be devoid of insulation is not 'connecting' to any other conductors.