The present invention relates to a radiation-emitting device (100), comprising at least one radiation source (110) configured to emit radiation of at least one wavelength towards a target (190) or towards a subject (192)； at least one space or surface (140) configured to place the target (190) or the subject (192) therein or thereon； at least one means (185) configured to control the at last one radiation source's radiation emission towards the target (190) or towards the subject (192)； wherein the radiation-emitting device (100) further comprises: at least one dual heating or cooling system (170) configured to heat or to cool the at least one space or surface (140) and comprising a Peltier device (171), said Peltier device (171) comprising at least two cuboids (172, 172') made of two semiconductor materials having different electron densities, said at least two cuboids (172, 172') being placed thermally in parallel to each other and electrically in series, interconnected with thermally conducting metal bridging plates (173, 173') and sandwiched between a non-conducting material reduced temperature cover plate (174) and a non-conducting material elevated temperature cover plate (174') and configured to be supplied with DC electric current via electrical connections (179)； at least one first heat exchanger (175) thermally connected as a heat source to the Peltier device's (171) reduced temperature cover plate (174)； at least one second heat exchanger (176) thermally connected as a heat sink to the Peltier device's (171) elevated temperature cover plate (174')； at least one fan or fan assembly (177, 178) configured to cause environmental air to flow along the at least one heat exchanger (175, 176)； at least one nozzle (180) configured to pass and direct the environmental air flow having passed the at least one first and/or second heat exchanger (175, 176) and heated or cooled towards the at least one space or surface (140) configured to place the target (190) or the s
