Coolants with low electrical conductivity can be used in direct or indirect cooling of electronic devices. The coolant has at least one glycol, water, at least one azole derivative, at least one ester of orthosilicic acid or alkoxy alkylsilane, optionally at least one tertiary amine bearing at least one 2-hydroxyethyl- or 2-hydroxypropyl-group, optionally at least one monocarboxylic acid, optionally at least one silicophosphonate, and optionally at least one further coolant additive.