I've heard a quick way to determine if the UV index is dangerous is if your shadow is shorter than you. Though location matters too.
I moved from Vermont to Texas and had to purchase an umbrella with UV protection to walk around during the day. The highest the UV index hits in the Vermont's summer is 6. In Texas, it's 11+ !!! 15 minutes and you're toast
I moved from Vermont to Texas and had to purchase an umbrella with UV protection to walk around during the day. The highest the UV index hits in the Vermont's summer is 6. In Texas, it's 11+ !!! 15 minutes and you're toast