  The Hot Spots constant for bounded smooth domains was recently introduced by
Steinerberger (2021) as a means to control the global extrema of the first
nontrivial eigenfunction of the Neumann Laplacian by its boundary extrema. We
generalize the Hot Spots constant to bounded Lipschitz domains and show that it
leads to an if and only if condition for the weak Hot Spots conjecture HS2 from
Ba\~{n}uelos and Burdzy (1999). We also derive a new general formula for a
dimension-dependent upper bound that can be tailored to any specific class of
domains. This formula is then used to compute upper bounds for the Hot Spots
constant of the class of all bounded Lipschitz domains in $\mathbb{R}^d$ for
both small $d$ and for asymptotically large $d$ that significantly improve upon
the existing results.
