Girls, I don't know what to think... The son hasn't been sucking on hi…

Girls, I don't know what to think... The son hasn't been sucking on his thumb for a day, I take it away. He behaves normally during the day, but he wakes up twice at night, but managed to put him down without a thumb. In the morning he woke up with a temperature of 38. Could this be related? I think now, either after the bath yesterday, or because of taking it away. For now, I'm not touching it, if it rises further, then I will knock it down.