Wooden panel paintings are commonly displayed in traditional churches, where they play to some degree a religious function in addition to their cultural value. They are subject to uncontrolled microclimatic variations that include weekly heating periods. The actual amount of these variations, as well as the consequence on the panel deformations, are insufficiently known. Such information is particularly required when a painted panel needs to be transported, either to be displayed in a different place like a museum or to a workshop for restoration, in order to assess the risk resulting from the change of ambient conditions and make the appropriate decision for their preventive conservation. The panel called "Le Couronnement d'Epines", about 500 years old, is made of 3 horizontal boards assembled through a pair of vertical crossbars. It is on display in the choir of Saint Didier church, Avignon, south of France, and presents a satisfactory conservation state. Our study focused on the upper board.