Normal sudoku rules apply. Numbers along an arrow must sum to the number in the arrow's circle. Two of the orange dots are thermometer bulbs and the third is the beginning of a palindrome. Which dot is which is to be determined. The palindrome is 10 digits long and goes around one of the heart shapes. Numbers increase from the bulbs of the thermometers on both sides of the heart shapes to the common end point at the base of the heart (r5c3 and/or r9c3 and/or r7c7).