A thermal model for human thresholds of microwave-evoked warmth sensations.
Riu PJ, Foster KR, Blick DW, Adair ER, · 1997
View Original AbstractHumans can detect microwave heating at just 0.07°C temperature rise, establishing clear thermal thresholds across wireless frequency ranges.
Plain English Summary
Researchers measured how much microwave radiation it takes for people to feel warmth on their skin at frequencies from 2.45 to 94 GHz. They found that humans can detect a temperature increase as small as 0.07 degrees Celsius at the skin surface, and this sensitivity works the same way whether the heat receptors are right at the surface or up to 0.3 millimeters deep. This study helps establish the minimum power levels where people begin to feel thermal effects from microwave exposure.
Why This Matters
This research provides crucial baseline data for understanding when EMF exposure transitions from undetectable to thermally perceptible. The finding that humans can sense temperature increases as small as 0.07°C demonstrates our bodies' remarkable sensitivity to microwave heating effects. What makes this study particularly relevant is that it establishes clear thresholds across a wide frequency range that includes common wireless technologies. The science demonstrates that thermal effects occur at specific, measurable power levels, and these thresholds become increasingly important as we're exposed to higher frequency technologies like 5G millimeter waves. Understanding these thermal thresholds helps distinguish between exposures that produce detectable heating and those that remain below the sensation threshold, though this doesn't address potential non-thermal biological effects that may occur at lower exposure levels.
Exposure Information
Specific exposure levels were not quantified in this study. The study examined exposure from: 2.45 to 94
Study Details
Human thresholds for skin sensations of warmth were measured at frequencies from 2.45 to 94 GHz.
By solving the one-dimensional bioheat equation, we calculated the temperature increase at the skin ...
The thermal analysis suggests that the thresholds correspond to a localized temperature increase of ...
We conclude with an analysis of the effect of thermal conduction on surface temperature rise, which becomes a dominant factor at microwave frequencies over 10 GHz.
Show BibTeX
@article{pj_1997_a_thermal_model_for_2539,
author = {Riu PJ and Foster KR and Blick DW and Adair ER and},
title = {A thermal model for human thresholds of microwave-evoked warmth sensations.},
year = {1997},
url = {https://pubmed.ncbi.nlm.nih.gov/9383246/},
}