Should I clip coat for summer?

[jowak]

My two golden retrievers (9 mos) have very thick, long coats. Should I clip their coats some for summer? I keep them combed at least 2 x per week and bathe them 1 x week. They are outside dogs and we live in the country. They go swimming in my nearest neighbor's lake almost daily.

Should I help them stay a little cooler with a haricut?