bio 2003 past paper mc

When temperature is 25C" .moew sweat is secrested to increase heat loss by evaporation.When it decreases to 15C", the sweat secretion decreases. Otherwise, the skin temperature will be lower than 25C" due to heat loss by evaporation.

Air temperature is always higher than the skin temperature in these situations.
There is no seating when the air temp. = 25C
So how can it decreases in secretion of sweat when air temp.= 15C

（2)不對!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!