High temp in creche

Could anyone with kids in creche advise what is happening with babies and toddlers regarding high temps? Anyone with young kids will know they get high temps a lot. Teething or just a cold. Creche would ring to say high temp and can give calpol and mostly that was the end of it unless very sick and you would collect. What is happening now? Is it the same or do you now have to collect and get covid test which is a bit OTT as over winter toddlers will have the test centres jammed up as they get so many high temps.