Attention this hot season has been on the heat and excessive electricity use, but ultraviolet radiation levels have gone far beyond the danger level and will remain that way for some time.
The UV index in Bangkok has routinely been at or above 11 for some time now and that is not about to change any time soon. Seven is considered high, 10 very high, and 11 and 12 are in the "extreme" category.
Those of us who go outside unprotected are being exposed to UVA and, to a lesser extent, UVB rays that can help cause skin ageing and wrinkles, eye problems, such as cataracts, and immune system damage. The skin can start to burn within 10 minutes with radiation levels this high.
The worst danger time is between 10am and 4pm. Clouds, especially the light clouds we are seeing, are not completely effective in blocking UV and the rays can be reflected by ground surfaces, even concrete.
Fortunately, most Thais, knowingly or not, follow many of the precautions suggested by the experts. First, they tend to stay out of the sun when possible and when going out they protect themselves with hats, sunglasses, protective clothing, and many are now using sunscreens as well – although that may have more to do with keeping skin colour light.
The experts say sunscreen should be applied 20 minutes before going outside. Check labels on sunglasses to see if they protect against UV and wear dark-coloured clothing if you are going to be in the sun for long periods.