Like our deodorant, Vulcan hair styling clay is also made with only naturals oils. Temperature extremes can impact the consistency of Vulcan. It is recommended that the jar be stored in temperatures above 63 degrees and below 85 degrees and out of the sun. If Vulcan gets too cold it can become very hard - it will still work but you will likely need some sort of utensil (like a butter knife or spoon) to get it out. Work the amount in your hands and it will warm up and melt for normal application. If you find that your hair clay melted in extreme heat, stir the clay up and place it in the refridgerator or a cool place to to get back to a solid state. If you have any questions, please contact us!