Over the past decade, there has been a growing interest in the development of cold atmospheric pressure plasmas for new biomedical applications. This so called Plasma Medicine concerns various clinical indications, including infectious diseases and recently, cancer treatment [1]. Besides encouraging demonstrations, it has been shown that tolerance and safety issues should be considered with great care for any therapeutic application [2]. A new generation of applicators, able to generate multiple jets from a single primary plasma jet, has been developed and qualified through in vitro experiments. Moreover, they have shown multiple interests (cf. the presentation of Th. Maho and colleagues in this conference). Using one of these multijet plasma sources, we have proceeded to in vivo treatments on healthy mice skin. Various assays have been carried, on nude mice (hairless mice) and CBl57/6 mice (hairy mice), which skins have different properties. The distance between the nozzle and the skin surface of the treated mouse can be adjusted by applying a spacer (in order to guarantee a constant gap during treatment - spacer not shown). The presence or absence of skin damages caused by the plasma was assessed as a function of time, distance and delivered power. Fig. 1: Assays of multijet plasma source from single Plasma Gun on Nude mouse (left) and CBl57/6 mouse (right) Between the applicator and the target, plasma jets could appear either clearly separated from each other or as a more diffuse discharge. Depending on the distance set between the nozzle and the tissue, different thermal effects and skin damages have been observed. The experimental results obtained from the characterization of these variables and their effects on the healthy mouse skin surface will be presented. These promising results will be used as guidance for the application of multijet plasma on decontamination procedures (cf. the presentation of Th. Maho et al.). Acknowledgements This work was supported by the CNRS PEPS project ACUMULTIPLAS and the ITMO Cancer in the frame of the Plan Cancer, project N°17CP086-00. References [1] M. Vandamme et al, Plasma Medicine 1(1): 27-43 (2011) [2] S. Kos et al, PLoS ONE 12(4), e0174966 (2017)