…tests with one or two layers of denim and/or cotton typical of
apparel worn indoors and observed an effective drop of approximately
10% of the differential between the liquid and the initial surface
temperature, which can translate to roughly 5 8C (9 8F). There is no
noticeable delay in the thermal response at the underlying surface on
the time scale of the insult process, given the typical absorbency of
the above materials.
The temperature of the spilled coffee in this case was 165° - 170° (see comments above), so the effect of the coffee on the skin would be that of 155° - 160° liquid, the damage exacerbated by the effect of the absorbent clothing holding the hot liquid against the skin.
