What Causes Itching And Burning In The Vagina?

Hi. My Vagina burns and itches. I had the same problem pnce last month and it lasted for a week or so. It happened when I had sex with my boyfriend or got fingered by him. Is this serious? I am really freaking out as it is happening again since yesterday. Do I need to consult a GYN? At first, I thought it is because of sunstroke (I live in a >90F place). But since it happened again I am lil worried.