a friend who’s a new daddy asked:

when he is fussy, small red spots start showing up 
and once he is back to normal they dissappear 
are those heat rash ? ?  
 just googled: Crying increases pressure in the blood vessels above the neck. It’s called the Valsalva effect, and occurs after straining at stool too. This sometimes breaks small blood vessels and leaves petechiae. Check with your pediatrician, but that’s all it sounds like. Vigorous little fellow, isn’t he?

A petechia (pronounced [pɨˈtiːkiə]), plural petechiae (pɨˈtiːkɪiː) is a small (1-2mm) red or purple spot on the body, caused by a minor hemorrhage (broken capillary blood vessels)[1].

The most common cause of petechiae is through physical trauma such as a hard bout of coughing, vomiting or crying which can result in facial petechiae, especially around the eyes. Petechiae in this instance are completely harmless and usually disappear within a few days.

(Just thought I’d paste this in so other new parents can find the info all in one spot.)