10m baby have red red on Face

Any Mummy Knows what is this on Baby Face? And what Causes it? Because im a new Mummy and im Worry coz is morning he was Fine suddenly Close to fetching him from infant care school call telling me he have Fever at first 38.4 at school then reach Home 37.0 and the other Side 36.4 #pleasehelp #advicepls #firstbaby