  We present the first preliminary results of the project \textit{ICED},
focusing on the face-on galaxy NGC4254. We use the millimetre maps observed
with NIKA2 at IRAM-30m, as part of the IMEGIN Guaranteed Time Large Program,
and of a wide collection of ancillary data (multi-wavelength photometry and gas
phase spectral lines) that are publicly available. We derive the global and
local properties of interstellar dust grains through infrared-to-radio spectral
energy distribution fitting, using the hierarchical Bayesian code HerBIE, which
includes the grain properties of the state-of-the-art dust model, THEMIS. Our
method allows us to get the following dust parameters: dust mass, average
interstellar radiation field, and fraction of small grains. Also, it is
effective in retrieving the intrinsic correlations between dust parameters and
interstellar medium properties. We find an evident anti-correlation between the
interstellar radiation field and the fraction of small grains in the centre of
NGC4254, meaning that, at strong radiation field intensities, very small
amorphous carbon grains are efficiently destroyed by the ultra-violet photons
coming from newly formed stars, through photo-desorption and sublimation. We
observe a flattening of the anti-correlation at larger radial distances, which
may be driven by the steep metallicity gradient measured in NGC4254.
