Preferring marginal investments that deliver greater utilisation and profits from existing infrastructure, skills and resources. Sweating the assets means the better utilisation of structures that are already in place and spending low extra or marginal costs in order to exploit better what's been built and spent already.
Nothing to do with health facilities for staff. It's all about making structures that are already built and paid for generate as much profit or revenue as possible without constantly adding to the size or scale of the business. It's not just about being mean either - it's sweating as much as possible out of what is already in place.