Hello, testing will be needed to determine if your concern is engine temperature related (such as with a thermostat that is stuck open, preventing the engine from reaching and maintaining the proper operating temperature), or climate control system related (such as due to internal controls for temperature blending not functioning properly inside the vehicle).
Once you determine which area the problem is coming from, troubleshooting that area can find the root cause of the concern.
RepairPal Certified shops can diagnose and repair your 2015 Chevrolet Equinox. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.