The temperature of a cats nose neither indicates health nor sickness. Since their skin temperature can flucuate throughout the day this may just mean that he is a bit warmer or there is more blood flowing to this area at that particular time. A cats normal body temperature can be as high as 102.5 which is nearly three degrees higher than our own so his skin temperature will always feel warmer. If however he is symptomatic: lethargic, not eating, sleeping more than usual I would consider taking him to the vet for an exam.
You can check his temperature rectally to get an accurate temp.