what does it mean when your air conditioner doesn't work

It's not turning on for some reason ... i live in california by the way and it's so hot already at night ... for me because i have anxiety and hot flashes... i get hot real easily at night and get an anxiety attack because of it.... 😡should i call someone to fix it?? i notice it works in the day time instead of the night.... and i don't get anxiety in the day...