how to concentrate in studies i got exams :(((((((((((( plzzzzzz tell i just cant sleep or cant study just thinking depresed thank you

I recently read that excessive sweating in children is a symptom of sleep apnea.
My daughter is about 3 and used to sweat really bad as a baby but doesnt anymore.
My son is almost 1 and is the same way. He sweats SO bad while he sleeps, it amazes me that he cant sleep with a blanket even when his skin is cold to the touch. He sleeps with a binki so he doesnt breathe through his mouth all the time. But he fusses all through out the night. I always figured it was because he was hot because he thrashes around while he’s fussing.
Could this be sleep apnea or could I just have hot natured babies?