Small red dots all over body

I am a 15 year old boy, and as of summer, i've been noticing very small red dots all over my chest, thys, and to some extent, my arms.

They are rather small, and generally occur where i am least tan. I never go tanning, so only my arms, face, and lower legs are generally tan.

My chest  is full of them. it's fairly gross, and rather embarassing. I vaguely remember a similar thing happening last summer, when i was 14. Can anyone tell me what they are, and how i may be able to get rid of them?