K.,
I'm afraid that I have no idea whether it would be alright to give him Advil or Motrin, but you definitely don't want to give him baby aspirin for his fever,as aspirin acts as a blood thinner and may cause him to have more nosebleeds. It may be a good idea to check with his pediatrician before giving him any type of over the counter medication, since some of them do make children more prone to nosebleeds.
If he has a low grade temp, it could be coming from his teething, or he may have a "bug" of some sort, or even an infection in his sinus passages, which is making him even more uncomfortable.
I thought I would post this to you since you mentioned that he had a nosebleed. If these continue, it could very well be coming from the heat in your home, especially if you have forced hot air heat. It may be a good idea to run some sort of a humidifier, or even a cool mist vaporizer for him while he sleeps, in order to put some moisture in the air, which may make him more comfortable, and less likely to have more nosebleeds.
If he should have any more of them, and you have a problem getting it stopped, putting ice on the back of his neck will help to stop the bleeding. Don't ever tip his head back, or the blood running down his throat may cause him to choke!
When my son (who is now 28) was small, every winter was an absolute nightmare, as he would get nosebleeds all the time from the forced hot air heat drying out his nasal passages, and when he got one, it took forever to get it stopped. Putting some humidity in the air in his room did help, but we finally had to cut his bedroom door in half, and leave the top half of it open, so that it didn't get too warm in his room, or he would have them every night, and they were nearly impossible to stop. He actually ended up in the ER twice, having to have his nose cauterized in order to stop the bleeding.
If your son continues to have nosebleeds, I would definitely make his pediatrician aware of it, and run a humidifier or cool mist vaporizer in his room during the winter months. His doctor may want to do some bloodwork, to check the Vitamin K levels in his blood, as, if it is too low, it will make him more likely to get frequent nosebleeds.
I hope this doesn't escalate into frequent nosebleeds because of your heat, but, if it does, the suggestions that I made above will definitely help. Good luck, and the most important thing to remember, if he should have one, is to stay calm, so you don't upset or frighten him, because that will only make the bleeding worse.
I hope this information helps!