nomerci, normal body temperature is 37 degree Celsius or 98.6 degree Fahrenheit, right? How much will sitting close to stove raise it? 38 degrees? 39 degree? If so, every cook should be having fever every time they come out of kitchen.
And even if lets say, its increased to 38 degree Celsius, will it cause over heating in newborn baby? Definitely not.
Believe me, breast milk temperature is not so susceptible to change in normal kitchen. If kitchen is too hot, mother's body thermostat will control any rise in body temperature via sweating or similar means unless as I said in condition of heat stress/stroke.
Our feeling hot doesn't mean our body temperature is raised. Body has an intact thermostat to check that.