  We show that equilibrium systems in $d$ dimension that obey the inequality
$d\nu> 2,$ known as Harris criterion, exhibit suppressed energy fluctuation in
their critical state. Ashkin-Teller model is an example in $d=2$ where the
correlation length exponent $\nu$ varies continuously with the inter-spin
interaction strength $\lambda$ and exceeds the value $d/2$ set by Harris
criterion when $\lambda$ is negative; there, the variance of the subsystem
energy across a length scale $l$ varies as $l^{d-\alpha}$ with hyperuniformity
exponent $\alpha = 2(1-\nu^{-1}).$ Point configurations constructed by
assigning unity to the sites which has coarse-grained energy beyond a threshold
value also exhibit suppressed number fluctuation and hyperuniformiyty with same
exponent $\alpha.$
