I have noticed in the past few weeks that I have an area in my St.
Augustine lawn that appears to be stricken with "Brwon
Patch". I would like to treat immidiately to prevent spreading,
however I do not want to cause more damage.

It has the characteristics of "Brown Patch" in that it is
somewhat circular in patter, the blades are brown and thin and dead
and when I pull on the brown or yellow blades, they pull up easily
indicating base damage.

To complicate things, the lwan was just planted 3 months ago from sod.
I have mowed it atleast 10 times. I also live in Texas where
temperatures have been in the high 90s to lown 100s for the past
several weeks and they are expected to be over 85 for the next 10
days. Every anti-fungal solution I see says to not use over 80.

What can I do now to prevent spreading and eliminate the fungus?
Shoudl I wait till it cools down to apply chemicals? I am at a loss
on what to do. Thanks in advance for your help.