Thats adorable. On my way to work I walk past a pond where there are usually florida cooters sunning. Once two were stacked on each other. bottom one saw me then scurried into the water, carrying the top one with him
(I agree with the comments about having a light, too. Even if it is warm in your house, you need to have a small heat lamp so they have a slightly warmer spot--30C, like Yvonne said--to access. They dry off better with a light over them, plus they still need a light for their mental health, so that they can recognize that it is day time, and they still need a UVB light so they can process calcium...)