  We analyse a huge and very precise trace of contact data collected by a
network of sensors during 6 months on the entire population of a rehabilitation
hospital. We investigate both the topological structure of the average daily
link stream of contacts in the hospital and the temporal structure of the
evolution of these contacts hour by hour. Our main results are to unveil
striking properties of these two structures in the considered hospital, and to
present a methodology that can be used for analysing any link stream where
nodes are classified into groups.
