2 week olds temperature.

My 2 week old woke up at 5 this morning. His nose sounded a little stuffy when he tried to breathe out of it. I changed him, fed him and went to put him back to bed like usual but he won't sleep and he just started sneezing and coughing a little. I checked his temperature and it's 99. That's high right? I should call the doctor when they open at 8?

Also the weather like drastically changed it went from 80 degrees on Wednesday to 50 degrees yesterday and we had to turn the heat on so I'm thinkkng that could have something to do with it?