## 4 Results
Body temperature is monitored in real time and compared with expected values based on the intensity of exposure. The curve shows a monotonically increasing trend because the acquired data show the direct, non-linear relationship between SAR and temperature variation. The temperature increase gradually increases for low SAR values, while it becomes more pronounced at higher SAR levels (>6 W/kg). This highlights a potentially exponential behaviour common in thermal dissipation processes on biological materials. Low SAR values (<2 W/kg) correspond to a negligible temperature change, compatible with regulated exposure limits for human safety. At higher SAR levels (>8 W/kg), the temperature rise reaches significant values, which may imply harmful effects or physiological changes in human tissue. Figure 10a depicts the incidence of SAR on human tissue in relation to the change in ambient temperature, assuming that the temperature in the indoor environment is 20 \({}^{\circ}\)C. Considering the different thermal increase scenarios, the curves show an increasing linear trend for all values of temperature variation. The increase in incidence, as shown in the figure, is proportional to the SAR value, becoming more pronounced as the temperature variation increases. As the ambient temperature changes, the incidence increases progressively, implying that this process amplifies the effect of SAR on human tissue. The observed linear trend confirms that the response of human  
The curves shown in Figure 10b demonstrate how the trend increases as the electromagnetic frequency increases. This implies that the energy absorbed by human tissue increases in direct proportion to the frequency of the electromagnetic waves. At the same time, the temperature increase becomes more pronounced at frequencies above 20 GHz, suggesting greater penetration and absorption at higher frequencies. The results confirm what was expressed in Section 3, i.e., how the proximity and angular position of the source relative to the human tissue significantly influence the absorption of electromagnetic energy and, consequently, the increase in temperature. The latest data monitored and acquired by the device concern the change in SAR and temperature for a moving subject within the indoor environment. The curves plotted in Figure 11 show two experimental configurations corresponding to distances of 1.0 m and 2.0 m from the electromagnetic source. All curves show an increase in temperature with increasing frequency up to about 10 GHz. Beyond this threshold, a slight reduction in the temperature change is observed due to saturation of the energy absorbed by the human tissue. The logarithmic frequency trend shows that the thermal response of the tissue is closely linked to the interaction between the wavelength of the electromagnetic waves and the dielectric properties of the tissue. Therefore, the distance from the source is a critical parameter for determining the thermal effect. Energy absorption decreases exponentially with distance, consistent with the laws of electromagnetic propagation and field attenuation. The results show that frequency and distance significantly influence the temperature change in human tissue exposed to electromagnetic waves. Figure 12 provides a quantitative representation of the energy absorbed per unit mass of biological tissue at varying distances and frequencies, where the decrease in SAR as the distance increases is determined by the inverse of the square of distance. In particular, at higher frequencies, the effect is less pronounced, indicating that energy absorption depends on the penetration of the electromagnetic field into the tissue. In contrast, SAR has low values at frequencies below 1 MHz, regardless of the distance. This behaviour is due to the longer wavelength and lower energy associated with low frequencies. At frequencies above 10 GHz, a decrease in SAR is observed due to the reflection effects of the electromagnetic field on the fabric surface.