Previous studies have shown that there is a large difference in the temperature of smoke in the upstream and downstream of a vertical shaft. but no quantitative study on the subject has been conducted. In this paper. a model experimental test was conducted to study the effect of a natural vertical shaft on the distribution of smoke temperature in tunnel fires. https://countryscenesaddleryandpetsuppliers.shop/product-category/full-double-stitched-rein-hl-5-8/