Hey guys, good to see that people are curious but I just wanted to clear a few things up. Essentially what happens in Ramadan is that you abstain from eating, drinking, having sex, etc from sunrise (fajr prayer) to sunset (maghrib prayer).
One of the main reasons why Muslims fast is, as mentioned, to feel for those living in poverty. Thus there is a big emphasis in Ramadan to be charitable and do what they can to help the unfortunate (including giving donations).
Another main aim of Ramadan is to, in a sense, restore your discipline and 'slap you straight'. By not being able to eat and drink for a certain period of time, you end up having a lot more time to think and reflect on your life, in hopes of coming out of Ramadan a more sincere and disciplined person. Some people also use this time to give up bad habits, like smoking.
As for the '1000s of people dying in hot countries from fasting', I live in Qatar (a desert) and no news of that has happened. Islam makes it clear that you shouldn't fast if: you're on your period, you're sick (or in a state where staying for prolonged hours of no food + water will affect you), you're diabetic, you have an eating disorder, you're a child, you're old, or if you're travelling. If you happen to live in a place where fasting is particularly difficult because of the time between sunrise and sunset (like in some Scandinavian countries last year where it lasted for 20 hours), you have the option of fasting according to the timings of Saudi Arabia.
Islam is quite accommodating, so if you have a valid reason why you can't fast then it's totally fine.