I read your question and I am sorry about your sleeping troubles.
It is hard to assess the cause with the little information we have. You should try to give more data like age, sex, medical history, medicines, exacerbating factors etc. so that we can help you better.
You don't give any info on whether you have checked your body temperature with a thermometer. If it is indeed increased then you should consult your doctor because you need to be examined for infectious or blood diseases, starting with a physical exam and blood count and then proceeding with possible further exams according to the findings.
If on the other hand your body temperature is normal it might be an
anxiety issue, you should try to avoid stimulants like caffeine products, spicy foods, alcohol.
Another possible reason especially if you're a woman in
menopause could be
hormonal changes which produce hot flushes.
Hope to have been of some help. Feel free to ask further questions.