The teacher doesn't have to single him out but tell the whole class that they will have a cool down spot (a small pop up tent is good, a barrel that a child can crawl in, under a table, a bean bag in
a corner, a rocking chair in
a corner, etc. are all good in
a classroom) and if a child feels upset, they can go there and not be bothered for a few minutes while they get themselves calmed down.