Hospital rooms at the Geneva University Hospital are hitting 34 degrees - with temperatures in the cafeteria up at 40.
Unions have demonstrated at the Trois-Chênes geriatric hospital, warning that elderly patients are at serious risk.
The hospital says 175 priority patients have been moved to air-conditioned rooms and portable coolers are being deployed.
Similar conditions have been reported at the cantonal hospital in Vaud, where unions recorded wards approaching 30.
Permanent cooling upgrades are promised from 2027, but for now patients and staff are relying on ventilators, cool cloths, and windows opened overnight.
Heat closes Geneva paddling pools
Crans-Montana looks to summer season after fire tragedy
MétéoSuisse warns of budget cuts
Rents rise Geneva - more than Zurich
Better passenger rights coming
Swiss football star joins Aston Villa
