Dogs Coat and Summer Heat???

I have a question about a dogs coat and the summer heat. I know a lot of people with long haired dogs shave them, or at least come close for the summer months. I got Roxy over the winter. She came to me shaved, been kept that way for years. Well she is a Lhasa and I have been working on growing her out. I have heard that her coat will actually help keep her cooler, by insulation, protection, ect. Is this true? I live in MI, so we spend most our days in the mid-to upper 80's during the summer, with heat spells into the upper 90's on occasion. This year I have no A/C. So should I trim her up, or leave it long? She has probably about half coat length as of now for a Lahsa. I wouldnt shave her completly, but take off most of the length. What would you reccemend? Im more concerned for her, than for my wanting a long coat. She does go out and play with the kids often for the entire day.

Well, some people think it's best to leave it long. I would think she'd be fine with a longer coat. It's true her coat can keep her cooler, plus it protects her from sun burn.