Help??

Ftm here. Sorry if it sounds stupid to ask but my 6 week olds body is pretty warm and a little sweaty and his hands and feet are ice cold. I checked his temperature and it was only 99.4. Anytime I call the on call nurse/ pediatrician they tell me to take him into the emergency room or Urgent Care. I was told not to worry about his temperature until it was 100.4. I'm just wondering if I should keep him in just a diaper? Or what. He's currently in a short sleeve thin onesie and I know it's not too hot in the house because I have the air running and it's a little under 70 degrees

***edited to add he is getting over an acute upper respiratory infection. He never had a high fever but is still very stuffed up and congested