If you're feeling stuck, check out my walkthrough of the solution below. Comments and ratings are much appreciated, and please be sure to check out my other puzzles here.
Rules:
Within the main 9x9 grid, normal sudoku rules apply.
Thermos: Numbers must increase along the thermometer from the bulb to the end.
Sandwiches: The numbers outside the main grid (none of which are given) equal the sum of the digits between the 1 and the 9 in that row/column.
(Note: Numbers outside the grid don’t have to adhere to normal sudoku rules: they don't have to be between 1 and 9, they can repeat in the row/column, etc.)
Solve on Penpa+ (thanks @Vebby!)
SPOILER ALERT Walkthrough of Solution
Puzzle:
Lösungscode: Enter columns 7 and 8 (18 digits, no spaces)
am 24. Dezember 2022, 13:48 Uhr von mathpesto
Added penpa+ link
am 19. Juni 2022, 19:59 Uhr von AnnaTh
Loved that one!