Good day. Has anyone encountered this?

Good day. Has anyone encountered this? A child was born on July 31st. Today after lunch he became restless, his belly swelled up, completely full, in the toilet he went frequently, refused from the chest but cried heavily, there's an unreal heat at home, it's over 32 degrees outside, measured temperature is 37.8-37.9, gave him medicine for the stomach ache, fed him and he fell asleep, changed diaper, but the temperature remains 37.8, breathing normal, called the maternity hospital, said to call a pediatrician, now I'm calling as well, can't call immediately, maybe someone will suggest something and calm down) while waiting for