Suit jackets will typically have sweat guards, and majority of suits are fully lined. Similarly trousers for the most part are lined to the knee, which actually extends below the knee.
+ shirt and underwear and air conditioning in cars + offices should keep sweating to a minimal.
Also choosing the right fabric for the weather/location is important. A lightweight summer suit of cotton, silk/wool blends which breathe much easier and are cooler will also help the temperature.
If you sweat profusely, or are out walking around outside in the 100+ degree heat, live in tropical areas etc. then you may need to dry clean more often, but it should still be kept to a minimum