Living in So. California, sun protection is a must just about year-round. My mil found a great company, called Sun Precautions, that sells sun protective (30 spf) clothing for adults and kids. While the selection for kids is limited, they continue to expand their line of clothing each year. Last spring (my son was about 18 mos.), I bought their Toddler pants (24mos), Kid's shirt (2T) and, Kid's legionnaire hat (they give the head measurements for each size). When we went to the beach I just had to put sunscreen on his feet (and lower calves), and his face. We were out when the sun was at it's peak and he never burned. No problems at all!! The only thing that was irksome, was that the fabric is woven, and doesn't stretch at all, so I have to buy a new shirt this year due to my son's large head! This time I'm buying one that zips in the front. The fabric washes nicely and dries in no time, so if you need to wash by hand between loads of laundry, it's not a big deal. And the hat has the longest neck drape I've ever seen on a child's legionnaire-type hat, so you REALLY don't have to worry about the neck being exposed. It also comes with chin straps that tie (another thing lacking in most hats I've seen). You may worry about the kid being too hot in a long sleeved shirt and long pants, but the clothing is so light and airy, my son was never hot. Sure he may have looked a bit different at the beach, but it was so much easier for me. They also sell swim clothing for those kids old enough to go into the water.
I highly recommend this line of clothing for anyone needing good sun protection for themselves and/or their children. It's pricey, but worth it! I just bought one set for him, and that worked just fine for me. They have a catalog, which I get in the mail, but you can find them online at www.sunprecautions.com. :D
