The aim of this proposal is to study starbursts in cluster
environments at epochs close to their formation. It is based on
the increasing evidence that elliptical galaxies went through an
infrared luminous phase at redshifts of z = 2-5, and the expectation
that infrared quasars at high redshifts are in rich protoclusters.
In this context, we propose a 10x10 arc min deep survey with CAM and
PHOT in the direction of high redshift objects known to have
large mass contents of dust and/or molecular gas.

As a second priority we propose a search for infrared luminous objects
in high redshift superclusters by mapping a larger area of 1 degree
square around one of the first priority targets.