http://www.laboratoriosilesia.com/upfil ... 978%20.pdf
This paper states that 'thermal' damage is akin to photoaging (related to sun exposure):
Severe skin aging may develop occasionally on the bakers’ arm, because they put their arm frequently in the hot oven and on the face of the workers who blow hot glass for many years. However, the biological effects of heat on human skin and their molecular
mechanisms through which heat act have not been fully understood. Heat shock is known to produce highly specific stress responses including the induction of a variety of heat shock proteins, which play a protective role against the harmful effects of stressful stimuli
[20,21]. In contrast to its beneficial effects, several studies have shown that heat shock increases the expression of collagenase and stromelysin mRNA in synovial and dermal fibroblasts, and have suggested that heat shock-induced collagenase expression may contribute to connective tissue degradation in disease states [22,23]. However, the molecular mechanisms of heat shock-induced MMP expression are not well understood.