Unreliable Sunburning History A limitation of the 6 integer Roman numeral Fitzpatrick SPT was reliance upon a history of sunburn after the first exposure of the summer. For those who reside in regions that have sun exposure all year (e.g. Arizona, Florida, California), the sunburning-tanning question after the first exposure of the summer was often irrelevant. Lastly, in the 1990s people began to use sunscreens to prevent sunburns, thus, those with sun sensitive skin may never have experienced sunburn and were unable to answer the question about ease of sun burning.