It's not just summer heat, but humidity also makes our homes feel hotter. A dehumidifier helps make it feel cooler by removing excess moisture from the air. Even if you're running the air conditioning and the house doesn't feel humid, the basement could always use one. Less humidity also means mould doesn't grow.
A downside of most dehumidifiers is the chore and mess of emptying the bucket. If you have a floor drain or sump hole, many dehumidiers have a hose attachment that can be used.
Now there are self-emptying, "bucketless" dehumifiers that feature an integrated pump, strong enough to push water up and out of a basement window or into a sink. They're a bit pricier than a bucket model but are virtually maintenance free.
Check out your local home improvement centre to find out more.