According to this Stack Exchange answer, glass reflects around 4-100% of the UV in sunlight depending on the angle of incidence. So you could probably get a sunburn if the angle is low enough (like if the Sun is almost directly overhead and reflecting off a vertical window).
What if you drained the oceans? ( www.youtube.com )
Link to original static webpage version: https://what-if.xkcd.com/53/
Can you get a sunburn from light reflected by a window pane?
Say I am sitting in the shadow, but the sunlight gets reflected by some window pane onto me. Does this contain enough UV light to give me a sunburn?