Melatonin functions differently intracellularly than when secreted by the pineal gland to induce sleep.

“at night the system is melatonin is secreted from the pineal gland it goes into the blood diffuses into the cell diffuses into the mitochondria and does the job do you think that that role of melatonin from the pineal at night is part of the reason why sleep is so restorative absolutely it's probably no coincidence then that when we fall asleep it's at least correlated with and in many ways caused by the reduction in core body temperature like it's very unusual for melatonin levels to be high when body temperature is high yeah these things normally are coordinated at night I'm not aware that it actually drops body temperature but it might I I'm just not aware of the literature but what you're describing is amazing I mean first of all most people's minds including mine are going to be blown by the fact that long wavelength light can actually go through clothing yes and skin and so you can imagine that if you have a minimum of clothing on whatever is appropriate for that context and you get some sunlight on your skin even on a cloudy day yes some of this should be coming through we could talk about that it's more UV light short wavelength light that's going to break through thick cloud cover correct uh cloud cover because it's water vapor and water vapor does absorb infrared it will be substantially less but much more than being inside and on a clear day or partially cloudy day uh we're getting a lot of red light long wavelength light and infrared and near infrared light coming through absolutely I think a lot”

“with infrared light and near infrared light all of the cells of our body the mitochondria are making melatonin this is wild and it perhaps it's a cellular extra extra brain you know it's outside of the brain store of melatonin”