Normal 6x6 sudoku rules apply. Digits on the slow thermo may not decrease starting at the bulb. Outside clues on the slow thermo must contain a digit, and that digit indicates the length of the first ascending sequence in that direction. For example, a row with 142536 gives a left clue of 2 (1, 4) and a right clue of 1 (6). ie a sequence can be only one cell.