Normal temperature of a jigsaw
The temperatures you're experiencing are normal for that type of saw. there will be little heat from the motor housing due to a fan fastened to the motor shaft for cooling, like a radiator fan in your car. The vent area does have warm air because that where the fan expels the heat from the motor and the gearbox. The vertical shaft holding the blade will be the warmest part of the saw with the exception of the blade when cutting. That's due to the constant friction of the shaft's up and down motion whether cutting of not. The gearbox for this motion is packed with grease but will still feel a little warm.