(a) SEM photograph of the fabricated metadevice. (b) The measured reflectance spectrum of the proposed metadevice with different stable heating temperatures. (c) Recording emittance (absorbance) of average emissivity in the LWIR band and CO₂ laser wavelength of 10.6 μm. (d) Relationship between heat temperature and observed temperature with reference of grey-body with average emission of 0.3 and 0.9, respectively. (e) Outdoor analysis of observed temperature with versus heating temperature and average emission.