Emma2064

I need help as soon as I can possibly get it. I had gotten a Macbook Pro for christmas this year (2015 but i think its a 2011 style, My aunt didnt tell me everything about it) and I own a computer but i cannot always use it. I have Second life on that computer (A HP) and I absolutly love the game. But i am confused, that because a Mac is a different type of computer, if downloading it will harm or overheat or cause any kind of virus on my Mac? I have read that it can overheat it and it will damage the fan (or whatever it is called) and that it can cause some kind of damage on the computer but it never explained what it was. Is this true? And if i did download it would the graphics be better like everyone is saying? I don't wanna damage it, and I need to know if the game can hurt the computer as quick as possible.