Whew, hot

Whew, it is hot outside. Walk out the door and a wave of humidity almost knocks you out. Welcome to summer! I've been planning this study abroad stuff that I'm gonna do and I just wonder about traveling. Since I'll be in Europe I kind of want to explore all over the place while there. My question is if hostels are safe. And, what if, I don't feel like exploring after my classes are over. Should I book the flight right after they are over, or give myself time to travel? I just don't know. Asking people doesn't get me anywhere either because they always say it's personal preference, or I don't know anything, or I don't care, or just something that doesn't help at all. *Sigh*