This is one of two puzzles based on the same concept. Both puzzles have the same ruleset, but the other one is harder because it requires more advanced techniques.
Normal sudoku rules apply.
Min-Max: Cells with arrows pointing inwards must be smaller than all of their orthogonally neighboring cells. Cells with arrows pointing outwards must be larger than all of their orthogonally neighboring cells.
Odd-Even: Cells with gray circles (which are not part of any thermos) must be odd digits, and cells with gray squares (which don't have any arrows on them) must be even digits.
Thermo: Cells along a thermometer must strictly increase away from the bulb end.
Lösungscode: Row 1 followed by row 3, no spaces.