text: 13' under rnost circ,mstance s, hands and. faces are those parts of the body that will be directLy e*'rrosed. for unwarned unp"otected hurnans. rn addition to the risk of shin burns, the eyes are quite ,"rr"iti.,ru to tne light ernitted. a r vi. erproslon could. cause flash blindrress at 20 kn. (I3 rniles) in daytirae and 85 kn. (53 mifes) at nighttine, and retinaf burns at somershat "rrort"t distances. lhife tlie eyesight will eventualry return after flash blinoness, it. ao"" of it in a criticaf situation, such as tlriving a car, could vel' cause severe accid.ents. Ilren if the inJuries are not too severe in.a ne.ti ca. "u"""r lr"n"a face and hands woul-d be a:*:::ll1* l*.li:."p in.the afternath of a nlr"i"u, explosion. Depend_ins on the crrcumstances' both of these types of injuries might arfect " t rrgl n.,-t"" of Deo,,.,.rcclue to the vast areas involved. 'ut<c 'L.,rue- vr !evr:,rs Fires 14' rn atldition to causing airect (flash) burns and ffash blindness, themaJ- "adiation will ignite combustible naterials. These night consist of curtains, rugs, beds snd furniture inside buildings as windowgr-ass vir-l not stop thernal- rad.iation noticeably' consequentr-y, erbensive fires iniioe buildings cou-ld be expect,ed. to result' even at distances where the l:-ast aoes-not cause too !.uch damage, Depend.ing on the weather, noisture. 1t_ the grounrt, etc., paper and plastic litter, dry wood., dry grass and leaves wou1d be ignitea oru" .'rJ"" or less large a?ea. ft is generelly believect" however, that the density of such conbustfble nateria_ls in many sections of urban areas in today's industriai society is not sufficient to eause extensive- -fi"es. A r-arge uncertainty is trre interaction betveen blast and fire. 0n one hand blast wir-r- extinguish rnany points of fire caused by thenlaf rad.iation, but on the other hand it wiu- increase- tire aensiiy-or conbustibre nateriaJ-s in certain areas by producing crebris and thus increase tire risk for a rater spreaa or rire. 75' Another source of fires in an ulban area wilr- be blast damage to stoves, water heatels' furnaces, e.lectricar. circuits uoo g;" iirr.". And. arhen irr"i"u, -o,.u.poou ,". used. over folested afeas - e.g., on a battl-;field _ the conbination of forestbLowdown through blast and possibre forest fires in dry weather cou]-d crearehazardous conditions for people in such areas.
analysis: The text appears to be discussing the effects of a nuclear explosion on humans and infrastructure, with a focus on the immediate consequences of the blast and radiation. The text mentions injuries to humans, property damage, and the risk of fires, which suggests that the category should be related to health and safety.