I I I I I30 20IIt^t3" -t-LOWer CUTVeS: Visibi I ity ca 20 km l0 ,000Yield ktl0 Fig. A:2 Distances for flash burns The distance frou ground zero where lhe thernal radiation nay cause skin burns depends stroigly on both yield and atmoepheric conditions ' The chart shows, as a function of yield, the theor€tically calculated distance for second- and third-degree burns in a clear atnosphere and rn a virtually eopty Epace.Al35/392 ]innex fage -LtlJ -O"nrrg. """""4 tV ttr""r"l ta ]t2' under cl-ear or fairly crear atmospheric conditions, h,'^s, beings wilr receiveseeond-degree burn injuries to unprotected skin at a considerabr_e dlstance fromground zero. An indication of what these distances might re is given ty trr" tigr".,second.-alegree burns over 30 per cent of the bod.y witl resul-t in serious shock and. ingenera"] require nedical treatment within hours -for surviva.I. Untreated third-degreeburns wilL prove fatal if about 25 per cent of the ski.n area has been damaged.cl-othes will provide some protection depending on the thickness and materia] of t-hefabric, but vi]l eventually transporb heat thiough to the skin ""d (;i catch fire.
**Analysis**
The text appears to be discussing the effects of a nuclear explosion on the human body, specifically the distance from the blast site where skin burns can occur. The language used is technical and scientific, indicating that the text is likely from an academic or educational source. The content is focused on a specific aspect of nuclear physics and its impact on human health, rather than any broader economic, social, or cultural issue.

**Category**
Health