When is it to hot to cut the grass?

I'm retired but I have a lawn business to keep me busy. When it is hot, the grass does better to be left at least 3" high. It keeps it moist and helps it stay healthy. With the high heat, water the grass often. Cut, no more that 1/3" the length and make sure that the mowers blades are sharp. Cut in the late PM when it's cooler. You cover your head, wear a dust mask if dusty and keep hydrated just like the grass. I cut grass all summer and the dust/dirt is more trouble than the heat.

You need advice on whether or not it's too hot to cut your lawn?

Hope you figure it out. That's a tough one.

I'll ask my wife. I'm not supposed to touch her new John Deere, and I don't! Sucks that I have to golf every night, but, it is what is. Gotta love those farm girls. BTW, its Africa hot in upper Michigan now too. (no offense ladies, my wife actually loves doing the lawn)

Right now it's too hot!
The best thing I ever did was get rid of the front lawn and install desert landscape. The backyard is still grass but it is not visible from the street. So if I'm lazy or the heat is excessive, I can always blow off mowing for awhile without receiving complaints.
During monsoon season it is humid and hot with lows in the upper eighties. I always mow early before the sun is up beating heat rays at me.
I like the look of a bit of lawn from the backyard deck but mowing is not an activity I look forward to.

Exactly! Right now.