Another important observation is that rays leave the reflected surface at the same angle at which they struck it.

另一个重要的注意事项是反射光线离开表面的角度与它们下降的角度相同。

She uses this heat index called the mean radiant temperature, which is basically how much heat is crashing into your body from the sun, from the air, from all the reflected surfaces.

她使用这个称为平均辐射温度的热指数，它基本上是有多少热量从太阳，空气， 所有反射表面撞击你的身体。