  The recently reported magnetic ordering in insulating two-dimensional (2D)
materials, such as chromium triiodide (CrI$_3$) and chromium tribromide
(CrBr$_3$), opens new possibilities for the fabrication of magneto-electronic
devices based on 2D systems. Inevitably, the magnetization and spin dynamics in
2D magnets are strongly linked to Joule heating. Therefore, understanding the
coupling between spin, charge and heat, i.e. spin caloritronic effects, is
crucial. However, spin caloritronics in 2D ferromagnets remains mostly
unexplored, due to their instability in air. Here we develop a fabrication
method that integrates spin-active contacts with 2D magnets through hBN
encapsulation, allowing us to explore the spin caloritronic effects in these
materials. The angular dependence of the thermal spin signal of the CrBr$_3$/Pt
system is studied, for different conditions of magnetic field and heating
current. We highlight the presence of a significant magnetic proximity effect
from CrBr$_3$ on Pt revealed by an anomalous Nernst effect in Pt, and suggest
the contribution of the spin Seebeck effect from CrBr$_3$. These results pave
the way for future magnonic devices using air-sensitive 2D magnetic insulators.
