The point is that if you are feeling actual thermal effects then you're probably in the danger zone of high power. They implied the effect was thermal "to make

The point is that if you are feeling actual thermal effects then you're probably in the danger zone of high power. They implied the effect was thermal "to make rooms feel much warmer", "like stepping into sunlight"; without clarification from them then my assumption is good that they were not talking about milliwatts.