What happens if you do not refrigerate soy milk?

I am a poor college student. During my spring break I got my parents to buy me a half gallon of Silk soy milk. I am used to buying soy milk that you don’t have to refrigerate. We left the soy milk in the garage. A few days later when I was packing up to go to back to school I saw the “Please keep refrigerated” notice. Is the soy milk safe to drink?