I am 12 yrs old and I have been getting dizzy and headaches at random times in the day. I also feel cold one sec. And hot the other . I know I don't have the flu or cold I know its something else but WHAT?

Are your parents aware that you are not feeling well? No one can diagnose your problem without actually examining you and perhaps ordering some bloodwork.

You need to see a Physician.

Honestly, you may not be sick at all. I've had days much similar to those you're describing.

Ironically, I found that just making sure I drank water consistently and eating a nice portion of food was the solution. When you don't drink enough water, your body becomes dehydrated, and often times dehydration leads to all that you describe... dizziness, headaches, random cold/hot sweats,

all mainly dehydration... H20 !