the portable infection resistant mat of the present invention is indicated generally by reference numeral 10 in the drawings . mat 10 , as illustrated , includes a cover 12 and around an inner padding 14 ( fig5 ). mat 10 can be of any size , however , a size convenient for use by children in a day care environment is preferred . for example , mat 10 can range in dimension from 19 inches by 46 inches to 24 inches by 48 inches . of course , the mat 10 can be much wider and much longer for use by an adult . the detailed description of the elements and manufacture of mat 10 now will be described in greater detail . cover 12 of mat 10 preferably is constructed from a material which is fire retardant and durable , such as approximately 10 mil to approximately 20 mil super strong vinyl . the cover material also is easy to clean and to disinfect . most important , however , is the fact that cover 12 is impervious to liquids , such as urine or other body fluids , and also is impervious to disease causing bacteria and impervious to vermin , such as head lice . the cover 12 of mat 10 includes a top sheet 16 and a bottom sheet 18 . it will be appreciated that the top sheet 16 and the bottom sheet 18 are constructed from contrasting color materials so that the bottom sheet 18 , which has contact with the floor , for example , is always placed on the floor and is not used as a resting surface ( fig3 ). thus , the sleeping side of mat 10 is distinguished from the floor side , providing more sanitary conditions of use . as best seen in fig1 - 4 , mat 10 is divided into segments , 10 a , 10 b and 10 c . it will be appreciated that mat 10 can include more than three segments or fewer than three segments , depending upon the desired length of the mat . the segmented mat allows the mat 10 to be folded for storage , as shown partially folded in fig4 . the top and bottom cover sheets are sealed along the seams s by radio frequency ( rf ) welding , as will be explained in greater detail below , to form a contiguous cover . however , at this point it will be noted that the cover sheets are welded together between the segments , to create thin , flexible hinge areas 20 and 22 , for example , which facilitate folding . of course if mat 10 had more segments it also would include additional hinge areas . referring to fig2 and 6 , it will be noted that when the hinge areas 20 and 22 are sealed by rf welding , discrete areas are not welded , thereby creating air passageways 24 and 26 . air passages 24 and 26 allow for air flow between the various segments , thus equalizing pressure within the various segments when a user lays on the mat , providing a more comfortable mat . air passages made by this method do not require hard inserts or tubing and thus are more comfortable . referring to fig2 it will be noted that the novel rf welding technique used to produce mat 10 produces seams s without stitch holes , thus eliminating another site of bacterial contamination and does not have threads that can unravel . furthermore , the manufacturing technique yields a mat 10 having rounded corners c , which is important for mats used by small children . each segment of mat 10 includes padding 14 . padding 14 preferably is a polyurethane foam of an appropriate thickness , preferably between ½ inch and 3 inches , most preferably 1 to 2 inches . the thickness of padding 14 should be sufficient to provide a padded , comfortable rest surface if mat 10 is placed directly on a floor . the mat 10 of the present invention generally is manufactured and constructed by the following steps : two aluminum bottom nests are attached to an aluminum turntable on a radio frequency ( rf ) vinyl welding machine ; a top sealing brass die is attached to a top heated platen on the rf welding machine ; a “ distance down ” limiting switch is set for the height of the die ; copper outside rf shields are set for the down stroke of the brass die ; a bottom limit switch is set for the lowest level for the brass die ; the power level is set for the rf power to the specific die used for sealing on the production run ; the pre - seal time , seal time and cool down time are set on the rf welding machine based upon the thickness and type of vinyl used for the cover ; the lower and upper plate current and power settings are sent on the rf welding machine ; the skip switch is set on the “ on ” position on the turntable drive ; the operation switch on the control panel is set to “ semiautomatic ”; a sheet or piece of cover vinyl is placed on one of the bottom aluminum nests so that it completely covers the aluminum ; on one end of the vinyl sheet appropriate tags are positioned under the vinyl on the aluminum nest ; the foam padding is appropriately positioned on the vinyl and centered inside the aluminum bottom nest ; one sheet or piece of vinyl is placed on top of the foam , completely covering the bottom pieces of vinyl ; the start button is activated on the rf welding machine ; the turntable rotates 180 degrees and then stops ; the rf welding machine upper platen compresses down on the foam and vinyl ; after settling for approximately 3 seconds , the rf power is applied and the two sheets of vinyl are welded together at their peripheral edges under the brass die and completely sealed ; the turntable rotates again and a completely sealed mat rotates out of the rf welding machine ; an operator picks up the mat and places it on an inspection table ; the operator pulls off any excess vinyl . on the outside seam is a tear seal that allows the vinyl to pull of cleanly . the excess vinyl is recycled ; the mat is inspected to see that all seams are completely sealed with no foam caught in the seal or any defects in the vinyl ; and it will be appreciated by those skilled in the art that various changes and modifications can be made in the mat of the present invention without departing from the scope of the appended claims . therefore , the foregoing description and accompanying drawings are intended to be illustrative only and should not be construed in a limiting sense .