0} \Phi_0(q_x(\zeta))\Phi_0(q_x(-\zeta)) -
                                     \langle \Phi_0(q_x(\zeta))\Phi_0(q_x(-\zeta)) \rangle_{\rm vac}$$ where $\langle \,.\,\rangle_{\rm vac}$ is the vacuum state, and we have set $$\label{whatisq}
 q_x(\zeta) = x + \zeta$$ for Minkowski space coordinate vectors $x$ and $\zeta$, tacitly assuming that $\zeta$ isn’t zero or lightlike. Thus, $:\Phi_0^2:(x)$ is an observable localized at $x$; strictly speaking, without smearing with test functions with respect to $x$, it isn’t an operator, but a quadratic form. Evaluating $:\Phi_0^2:(x)$ in the global thermal equilibrium state yields a monotonous function of the temperature. This is also the case for mass $m > 0$, only the monotonous function is a bit more complicated. So $:\Phi_0^2:(x)$ can be taken as a “thermometer observable” at $x$. As in our simple model the KMS-state for $\Phi_0$ is homogeneous and isotropic, $\langle : \Phi_0^2:(x) \rangle_{\omega_{\beta,e_0}}$ is, in fact, independent of $x$. Let us abbreviate the Wick-square “thermometer observable” by $$\label{Wicki}
 \boldsymbol{\vartheta}(x) = :\Phi_0^2:(x) \,.$$ Starting from the Wick-square one can, following [@BOR], form many more elements of $\boldsymbol{\Theta}_x$. The guideline was that these elements should be be sensitive to intensive thermal quantitites at $x$. This can be achieved by forming the [*balanced derivatives of the Wick-square of order $n$*]{}, defined as $$\begin{aligned}
\eth_{\mu_1\ldots\mu_n}& :\Phi_0^2:(x) \\ 