usual height. the yield likely to be the smallest in decades. all our grasses, all our legumes have died. not died, but dried up. reporter: cattle ranchers are selling cows they can t afford to feed. yet another heat wave this week is only making matters worse. baking the midwest and firing thunderstorms elsewhere. here in houston, lightning killed these two men as they watched a soccer game. they had just finished playing. it started raining and they took cover under the trees. and the lightning struck the trees. reporter: sadly, the men were in precisely the wrong place. half the people that die from lightning strikes in the u.s. this year were standing under trees and the other half were out in open fields. reporter: lightning typically strikes the tallest object around. the current can travel down the tree and into your body. experts say the best thing you can do is seek shelter in a large enclosed building. the lightning will travel through the wiring or the