It's radiation, not heat that causes sunburn!
The sun provides us with light and heat, but what many of us don’t know, or often forget, is that it also emits radiation, and overexposure to radiation is what causes sunburn. While it’s not difficult to see why many of us believe our skin burns due to lengthy exposure to the sun on hot days, heat has nothing to do with the red, sore, sunburnt skin that many South Africans have come to know.
Radiation is received in three forms; infrared, visible and ultraviolet (UV). UV, specifically UVB, is the form of radiation that provides no heat, but causes harm to human skin in the form or redness and pain. This means that even on cloudy, cool days, up to 80% of UV rays can still penetrate the clouds and cause damage to your skin. While it can be tough to disconnect heat from sunburn, (as we can physically feel our skin burning on extremely hot days) the burning sensation we feel in fact comes from infrared radiation, which does not cause sunburn.
This means that we should, in fact, take note of the UV index and not just the temperature to determine whether our chances of getting sunburnt are high or not. According to Weather SA the UV index predicts UV intensity levels on a scale of 0 - 10+, and the index can be followed as below:
3 - 4 - Low: A hat and sunscreen is recommended.
5 - 6 - Moderate: A hat, sunscreen and remaining under shade is recommended.
7 - 9 - High: Together with the recommendations above, it is advised to stay in the shade between 10:00 and 16:00.
10+ - Very High: Together with the precautions above, it is advised to stay indoors or in the shade between 07:00 and 17:00.
So the next time the clouds roll in and the temperature drops slightly, check the UV index on your local weather channel to see whether your chances of sunburn are higher or lower on any given day. Keep a sachet or two of EezySun sunscreen in your bag or wallet, and you can make sure your skin is always protected from those harmful UVB rays.