  We study real quadratic fields $\mathbb{Q}(\sqrt{D})$ such that, for a given
rational integer $m$, all $m$-multiples of totally positive integers are sums
of squares. We prove quite sharp necessary and sufficient conditions for this
to happen. Further, we give a fast algorithm that solves this question for
specific $m$, $D$ and we give complete results for $m \leq 5000$.
