Blood temperature increse

Blood temperature of one creature of your choice whit in your range drasticly increse to the poined where they can and probably will take damage of  4d6 fire damage and is blinded on a failed con. save. On a succesful save it takes 2d6 fire damage and the spell ends.  At the end of each of its turns, the target can make another Constitution saving throw. On a success, the spell ends.