There are two distinct species of elephants: African elephants (Loxodonta africana) and Asian elephants (Elephas maximus). They both live in hot, somewhat inhospitable environments, with occasional droughts and plenty of predators to threaten prey animals, but their adaptations have helped them to survive these conditions.
Elephants' massive size is a great anti-predator adaptation. Although they're technically prey animals, rather than predatory ones, adults are so large that they're invulnerable to attacks from wild animals. Humans are the only predator that can threaten them. However, baby elephants can be attacked and killed by animals such as lions, tigers and hyenas. To stop calves being harmed, adults in a herd will group the young together and form a protective circle around them.
When you're a large creature with a short neck, a trunk is an extremely useful part of your anatomy. Not only does it help elephants to reach food high up in branches, it also allows them to get to food and water on the ground, which they otherwise wouldn't be able to access. Additionally, they use their trunks to make calls and other sounds to communicate with one another and warn their herd about any potential threats.
Although their tusks can bring elephants some trouble, as they're mainly poached for their ivory, they're also very useful. They use them to strip bark and soft wood off trees, which they subsequently eat. Their tusks can also help them to survive through dry spells, as they use them to bore down into the earth and find water in dry riverbeds. In addition, they use them to dig in the ground and uncover salts and other minerals that are vital to their diets.
Elephants live in hot conditions and need to be able to cool themselves down. Since they're unable to sweat, they've adapted another solution. They flap their large ears to help cool the blood in their capillaries and distribute the cooler blood through their bodies. This process can lower their blood temperature by more than 10 degrees Fahrenheit. Although Asian elephants have smaller ears than their African cousins, the process is still as effective.