Leaf burn in middle

[matamus]

I was wondering what you all might think this is, it was quite hot in the room, which it is the mother room, an about half the moms are showing this on some of the top leaves. Sulfur was just burned for 6 hours, four nights ago an temps. did get in the upper 80's I was thinking this could be a number of things heat, sulfur, an a tad close to the lights. sorry for the crappy pictures it was taken with my iphone
thanks for all your help in advance

 

[Seamaiden]

I've never seen burning like that before. I could only guess that it was the sulfur.