Help!!!

I have never in my life got a cold sore. This small pimple look a like thing popped up on my lip it hurts but other than that nothing. Can this be a cold sore or can it be a heat blister as I’m currently super sun burn all over my face and shoulders due to being in the lake. I was reading that cold sores can also pop out cus the heat and stress which I’ve been stressing as well. I just want to get well educated sorry