As discussed in (3. Why radiation did not cause images), the crystallinity of the flax fibers in all of the parts of the Shroud that were not scorched has not been significantly degraded.
The Arrhenius Law describes the effect of temperature on rate constants for all consistent chemical reactions, as follows:
k = Ze-E/RT
where k is the rate constant at any specific temperature, Z is the Arrhenius pre-exponential (related to the probability that any specific molecule(s) will react), E is the Arrhenius activation energy, R is the gas constant, and T is any specific, constant absolute temperature (degrees Kelvin). If the image were a scorch or any part of the Shroud had been heated enough to make significant changes in the rates of decomposition of any of its components, we would see changes in the structure of the flax fibers and blood. The blood still evolves hydroxyproline on mild heating, and the cellulose crystals are largely undistorted. Image and control fibers show identical crystal properties. The image is not a scorch. The cloth was not heated, not even boiled in oil.