about 85 u00b0 c for this reason and as it can be promptly verified by any person skilled in the art the temperature in the heating environment as well as the necessary time for the wood to be maintained therein will depend upon various factors such as the thickness of the logs or boards to be treated their density among others the essential aspect however is that the temperature and the time are established in such a way that the heating of the core region can reach the above mentioned temperature range after the heating step wood is then left to cool in an environment that preserves its moisture contents within a range of from 95 to 100 it is necessary that the cooling step is carried out in this way in order to achieve the desired results so that the moisture on the wood surface will not be lost after the heating otherwise the possibility of occurrence of surface cracks increases due to the internal and superficial moisture gradient that is generated it must be observed that that occurrence of cracks may be potentialized in function of numberless other factors such as the predisposition of the material to form cracks caused by growth stress inadequate cutting of the logs into planks among others however even in these cases the formation of cracks is substantially reduced by the process of the invention preferably the cooling step is carried out by covering the heated material with.