Does artificial heat (shower/tea) affect diurnal rhythms in humans? I've been reading that over the course of the day, **human body temperature follows diurnal rhythm** with the lowest body temperature observed some time close to the middle of the sleep episode, while the peak body temperature is observed some time close to sunset. Circadian rhythm on Wikipedia I'm interested **if humans have internal organ systems or brain "sensors" that "read" the body temperature as a part of synchronizing their own internal circadian clock to the master clock of the human body.** If there are indeed such sensors, then I'm interested if they can be thrown "off track" by artificial heat sources, like hot food, drinks or showers.

Yes, the human body has thermoreceptors that "sense" the current temperature, but these merely help with regulation--you know, shivering to raise internal body temperature and sweating to cool via evaporation. The hypothalamus is primarily responsible for making sure that the circadian rhythm itinerary is adhered to reasonably well. So no, if the thermoreceptors detect that the body temperature is 97 deg F but it's 5 pm, the body will not "get confused" and decide that it is actually 4 am because a human body is about 97 deg F at 4 am.