Toes turning a dark shade(like dark blue) ?

When Im really cold because of the temp. Surrounding me, and I'm sitting down, all my toes from both feet turns really dark shade of blue . I men like If they didn't have life or something it goes away when I stw d up and walk around. Also help when I get out of the cold room.( usually a temperature of 24 degrees celcius is what triggers this. It also happens in my hands but less noticeAble. My fingernails get all purple and it hurt ALOT. And then when iget out of the cold into a warm or hot environment, my hands turns red, sting abut and hen resume normal color. Oh and I'm 14 and female. Thank you!!!