I will discuss studies where Planck and Herschel data are used to investigate dense interstellar clouds. The Planck Catalogue of Galactic Cold Clumps (PGCC) was made public earlier this year. It contains over 13000 cold and compact dust clouds and represents a cross section of current and future star-forming sites within the Milky Way. We have analyzed Herschel observations of over hundred fields with more than 400 individual Planck clumps. I will present new results on dust properties in these clumps and discuss the complementary work done on the extinction mapping of interstellar clouds. In many of our studies, the accuracy of distance estimates is a major source of uncertainty. I will describe the work that was done in connection with PGCC and the improvements expected from the use of Gaia data.