Does wearing linen reduce skin temperature by more than 3°C?

Question

There are many claims around about clothes made of linen being useful in warmer climates. Usually it includes explanations such as a better transportation for sweat so it can evaporate more easily, or that it allows for wind to pass through. I'm wondering about the claim that skin temperature is reduced by over 3°C...

In hot weather people wearing linen clothes have been found to show a skin temperature of 3°- 4°C below that of those similarly dressed in silk or cotton

(e.g. here, here, and here)

Is skin temperature actually that much lower, compared to cotton?