Nechusho (heat strokes) are unfortunately very common occurrences during Japanese summers because of the relentless humidity and intense temperatures. So out of necessity, Japanese people have become masters of protecting themselves from the mighty sun.
One common sight is the use of foldable sun umbrellas (can double as rain protectors) designed to block UV rays. People typically carry them in their bags and purses until outside–both convenient and effective. If you prefer not to carry around a sun umbrella, at the very least, I highly recommend putting on a hat and using plenty of sunscreen, which you can find at pharmacies, supermarkets and even convenience stores.
You might even see ladies with full-on arm covers and a hardcore sun visor (a face cover made with see-through plastic). That’s when you know protecting yourself from the sun in Japan is serious business.