Does anyone know what actually happens if you have some mild sun exposure after an ipl treatment?

Are you just more in danger for burning... or what's the deal? It's been two days since my first session, but I just got locked out in the 6 o'clock sun for 40 minutes... normally this wouldn't do anything, I wouldn't burn or even tan because the sun is so low at that time of day. BUT I'M FREAKING OUT!