What is the operating temperature recommended for achieving optimum service life?

The recommended operating temperature for achieving optimum service life varies widely based on the specific device or material in question (such as electronics, machinery, etc.). Generally, manufacturers provide guidelines in a product's technical specifications or user manual.

For many electronic devices, an ideal operating temperature is usually between 20°C to 30°C (68°F to 86°F). For industrial machinery, the recommended temperatures can be higher, depending on the type of machinery and its components.

To get the most accurate recommendation, it's best to refer to the specifications provided by the manufacturer of the specific product you're interested in.