feeling very weird...

i am not very old(do not wish to tell age but under 20) but i am having a very weird feelings and it always goes away in the afternoon. it's around 40 degrees in the morning and around 50-60 in my class but i start feeling very hot and this is sweating hot!  then after a while i start feeling very cold like its freezing in the room.  this switches from cold to hot for a while then after all this i feel a little headache then it goes away.  later i feel it again.  is this a mental problem or something else?  because i'm not sure what it is i would like to know what it is and how i can stop this because it's coming at the most awkward moments.  


This discussion is related to Still having feeling of hot head and cold body (chills).