Two weeks ago, I was really busy with work and it was like continuously non stop for days. I kind of noticed that physically I was going to fall apart. With this excuse, I went for a massage and hopefully feel recharge again after a thorough "flushing" of toxins in my body. But unfortunately sometimes it ended with a fever the next day. Sigh.... To me this is nothing new at all as previously it did happen to me before.
According to my understanding, after massages (especially strong pressure massages or massages that manipulate deep tissues) it increases the circulation of the fluid in the muscles and that increases the body temperature to 1 or 2 degree higher. But sometimes due to lack of exercise for a long time and been working too hard it causes our body to accumulate too much toxins like lactic acid and imbalance of hormones. That will lead to slight fever as the body need more times to flushes out the toxins and rebalance the body.
Note: So my advice is if your daily routine is always stressful and tiring, try either not to stop exercise (simple stretching for 10 minutes daily is good enough) or go for a massage as a form of maintenance and not expecting it as a form of recovery.