Cold pack

Abstract

A cold pack that includes an enclosure having a powdered solute and a liquid sealed inside the enclosure. The powdered solute and the liquid are segregated within the enclosure by a membrane. Rupturing the membrane mixes the liquid with the powdered solute to produce an endothermic solution within the enclosure. Substantially all of the powdered solute rapidly dissolves within the liquid such that the cold pack quickly reaches its cooling temperature. In another aspect, the cold pack includes an absorbent core within the enclosure. The absorbent core retains the endothermic solution such that the absorbent core spreads the endothermic solution throughout the enclosure. Spreading the endothermic solution throughout the enclosure produces a uniform cooling temperature throughout the cold pack.

1 . A cold pack comprising: 
 an enclosure;    a powdered solute within said enclosure;    a liquid within said enclosure; and    a membrane segregating said liquid from said powdered solute, wherein rupturing said membrane mixes said liquid with said powdered solute to produce an endothermic solution within said enclosure.    
   
   
       2 . The cold pack of  claim 1  wherein said liquid is water.  
   
   
       3 . The cold pack of  claim 1  wherein said powdered solute is ammonium nitrate.  
   
   
       4 . The cold pack of  claim 1  wherein said membrane is polyethylene.  
   
   
       5 . The cold pack of  claim 1  wherein each piece of said powdered solute is substantially between 0.001 and 0.025 inches.  
   
   
       6 . A cold pack comprising: 
 an enclosure;    an solute within said enclosure;    a liquid within said enclosure;    a membrane segregating said liquid from said solute, wherein rupturing said membrane mixes said liquid with said solute to produce an endothermic solution within said enclosure; and    an absorbent core within said enclosure, said absorbent core retaining said endothermic solution to spread said endothermic solution throughout said enclosure.    
   
   
       7 . The cold pack of  claim 6  wherein said solute is a powdered solute.  
   
   
       8 . The cold pack of  claim 6  wherein said absorbent core is an absorbent layer.  
   
   
       9 . The cold pack of  claim 6  wherein said membrane segregates the liquid from the absorbent core.  
   
   
       10 . The cold pack of  claim 9  wherein rupturing said membrane causes said endothermic solution to be retained by said absorbent core.  
   
   
       11 . The cold pack of  claim 6  wherein said membrane is polyethylene.  
   
   
       12 . A cold pack comprising: 
 an enclosure;    a powdered solute within said enclosure;    a liquid within said enclosure;    a membrane segregating said liquid from said powdered solute, wherein rupturing said membrane mixes said liquid with said powdered solute to produce an endothermic solution within said enclosure; and    an absorbent core within said enclosure, said absorbent core retaining said endothermic solution to spread said endothermic solution throughout said enclosure.    
   
   
       13 . The cold pack of  claim 12  wherein said powdered solute is substantially between 0.001 and 0.025 inches.  
   
   
       14 . The cold pack of  claim 12  wherein said membrane segregates the liquid from the absorbent core.  
   
   
       15 . The cold pack of  claim 14  wherein rupturing said membrane causes said endothermic solution to be retained by said absorbent core.  
   
   
       16 . The cold pack of  claim 15  wherein substantially all of said powdered solute is dissolved in said liquid to form said endothermic solution before said endothermic solution is retained by said absorbent core.  
   
   
       17 . A method of cooling a portion of a body, the method comprising: 
 segregating a powdered solute from a liquid, the powdered solute and the liquid both being inside of a cold pack;    mixing the powdered solute with the liquid to form an endothermic solution within the cold pack; and    applying the cold pack to the portion of the body.    
   
   
       18 . The method of  claim 17  wherein mixing the powdered solute and the liquid to form an endothermic solution includes rupturing a membrane that segregates the powdered solute from the liquid within the cold pack.  
   
   
       19 . The method of  claim 17  wherein mixing the powdered solute and the liquid to form an endothermic solution includes dissolving substantially all of the powdered solute within the liquid and then distributing the endothermic solution throughout the cold pack.  
   
   
       20 . A method of cooling a portion of a body, the method comprising: 
 segregating an solute from a liquid, the solute and the liquid both being inside of a cold pack;    mixing the solute with the liquid to form an endothermic solution within the cold pack;    distributing the endothermic solution throughout the cold pack; and    applying the cold pack to the portion of the body.    
   
   
       21 . The method of  claim 20  wherein mixing the solute and the liquid to form an endothermic solution includes rupturing a membrane that segregates the solute from the liquid within the cold pack.  
   
   
       22 . The method of  claim 20  wherein mixing the solute and the liquid to form an endothermic solution includes mixing a powdered solute within the liquid to form an endothermic solution.  
   
   
       23 . The method of  claim 20  wherein distributing the endothermic solution throughout the cold pack includes retaining the endothermic solution within an absorbent core.  
   
   
       24 . The method of  claim 23  wherein retaining the endothermic solution within an absorbent core includes retaining the endothermic solution within an absorbent layer.  
   
   
       25 . A method of cooling a portion of a body, the method comprising: 
 segregating a powdered solute from a liquid, the powdered solute and the liquid both being inside of a cold pack;    mixing the powdered solute with the liquid to form an endothermic solution within the cold pack;    distributing the endothermic solution throughout the cold pack; and    applying the cold pack to the portion of the body.    
   
   
       26 . The method of  claim 25  wherein mixing the powdered solute and the liquid to form an endothermic solution includes rupturing a membrane that segregates the powdered solute from the liquid within the cold pack.  
   
   
       27 . The method of  claim 25  wherein mixing the powdered solute and the liquid to form an endothermic solution includes dissolving substantially all of the powdered solute within the liquid and then distributing the endothermic solution throughout the cold pack.  
   
   
       28 . The method of  claim 25  wherein distributing the endothermic solution throughout the cold pack includes retaining the endothermic solution within an absorbent core.