How does altitude, distance from the ocean, amount of sunlight, distance from the equator, and ocean currents affect polar climate?

The altitude is usually low. Tropical places are mainly on the ocean, that's usually why it's so hot. They are usually close to the equator, but not right on it. The tropics get a lot of direct sunlight, so wear that sunscreen! The ocean currents are warm, so they bring along warm water. All of those help make the tropics the way they are.
 
Hope this helps