Actually, Friday was the first day of 'sumer', so it has already arrived.
Which makes this a perfect time to correct a misconception I held, which I bet many of you did too.
I always thought that you couldn't be damaged by the sun if you were in a closed car.
(Roll your windows down and stick your arm out, or drive a convertible top-down, sure...)
But an Alert Reader (Dave Barry isn't the only one) pointed out a series of studies which show that while most car windshields do filter out UVB light which causes sunburn, the side windows may not.
More important, neither fully blocks out UVA light, which can cause even worse damage, including cancer.
In patients who were frequent drivers and who had malignant melanoma, the most deadly of skin cancers, some 74 percent of tumours were on the left side of the body.
Another even larger study confirmed those results, and found that men were even more likely to have left-side cancers than women. The suggestion is that women may spend more time in the passenger seat, and hence may show less 'laterality', as the researchers put it.
Once while in Australia a couple of years ago I recall hearing that cancers on the back of the hands was becoming an increasing issue down there, perhaps due to those parts of the body being exposed to the sun. Another reason to use the 'quarter-to-three' hand position on the steering wheel!
Makes what your Mom told you even more important - even when driving in a closed car, "Wear Sunscreen!"