Is there a reason that my body temperature feels as though it's higher if i get 4 hours of sleep or less the night before? a small amount of sleep one night always makes me feel warmer the next day, but temp readings are always normal..?

Nervous impairment: It is widely documented that lack of sleep causes the body to be less able to regulate perceptions of hot and cold. This is due to impaired descending nerve pathways, facilitated spinal excitability and sensitized peripheral pathways to cold, pressure and pain. It is not actually that your core temp is more hot or cold, but that your nervous system is more sensitive to the perceptions.