  Multifractal measures are applied to three IRAS galaxy subsamples selected by
colour from the PSCz catalogue. As shown by generalised dimension spectrum, hot
IRAS galaxies are found less clustered than cold galaxies, but the difference
is very weak. An alternative tool, the conditional multifractal dimension
spectrum reveals apparent peculiarity of the distribution of hot galaxies,
especially at high orders. The conditional multifractal measure is basically
measuring the environment of selected galaxies. A detailed analysis of the
distribution of galaxies with their number of neighbours turns out that cold
galaxies are more likely living in over dense regions than hot galaxies.
Further studies suggest that, since the colour of IRAS galaxies is a good trace
of star formation rate, it is possible that we have statistical evidence here
for enhanced star formation rate due to galaxy interactions
