increased body temperature during meditation

Is it common during samatha for the body temperature to rise enough to cause some isolated forms of sweating? Specifically around the head, like where a hat would set and sometimes across the upper chest and shoulders? It doesn't happen every time but at least several times a week. The room temperature is well regulated and in no way warm. I also noticed that there may be a correlation to some insomnia on the same nights that the sweating occurs during the meditation.