  We give necessary and sufficient conditions for a cdh sheaf to satisfy Milnor
excision, following ideas of Bhatt and Mathew. Along the way, we show that the
cdh infinity-topos of a quasi-compact quasi-separated scheme of finite
valuative dimension is hypercomplete, extending a theorem of Voevodsky to
nonnoetherian schemes. As an application, we show that if E is a motivic
spectrum over a field k which is n-torsion for some n invertible in k, then the
cohomology theory on k-schemes defined by E satisfies Milnor excision.
