As this is a cheap version of the board I suppose Udoo will not guarantee an operating temperature. The industrial version of Seco (SBC-B08) is guaranteed between 0 and +60 dgr C. There are also boards that are guaranteed on larger ranges. http://www.seco.com/prods/it/category/single-board-computer.html
The Neo is tested until 60 degree C http://www.udoo.org/udoo-neo-in-the-oven-extreme-temperature-test/