The power switches and fan motors are not spark-free and can pose a serious ignition hazard.
Be aware of the direction of the heat. Never direct the air flow towards one's body. Heat guns can produce up to 1100°F of flameless heat at the nozzle which can ignite clothing and can cause severe burns.
Do not use an extension cord to power a heat gun.
Never block the inlet grill or obstruct the air flow of the unit while in operation. If the air flow is reduced, the heat gun will overheat and potentially catch fire.
Never leave a heat gun unattended during operation or cool-down and allow the heat gun to cool before storing it.