No Cornwall is not hotter than in-land. The sea regulates our temperatures so we neither have extremes of cold or heat.I have too, it is called the UK summer and it last for about 2 weeks a year... again we live in the UK, maybe Cornwall is a bit hotter but it is still the UK, the vast majority of the time the aircon is not brining the temperature down relative to the outside.
You're telling me honestly that, in your experience, the inside of an office is always hotter than the outside? We've worked in very different places then.