Uuggghhhhh scared

My kids cousins were over the other day for maybe a half hour. Well now one of them has an super high fever. They're 8 so they didnt have anything in their mouths here etc but he and my older son played and shared electronics and now I'm TERRIFIED we were all exposed. I have a 2 month old:( so now I'm going to obsess and freak out for probably the next week or more. Ugh. I hate sickness. Does anyone know if it's worth worrying about? Idk if things are just contagious for uncertain amount of time etc. I can only hope lol I'm gunna drive myself crazy.