Yesterday I watched the news on TV where a fire department used a ladder truck to rescue a child that had climbed a tall tree and got his leg caught between a couple of branches.The fire men were decked out in their heavy fire fighting clothes and helmets as they made the rescue.Those clothes are hot and heavy. Why do they wear them to non-fire events?Carry them in the trucks and put 'em on as needed makes more sense.
The trick is to start out cold enough and have enough insulation. First, you need a dewars flask (thermos bottle). But you only want the silvered glass liner, and that must be mounted securely using something like styrofoam in a sturdy container that has plenty of space to fill with lightweight insulation, including over the top. Fill the spaces around it with styrofoam beads or something like that. Reflective material is a plus, so wrapping the outside with aluminum foil (shiny side out) can't hurt. Lining the box with foil (shiny side in) is also a plus. Corrugated cardboard is good for the box, make it sturdier by gluing it up to make it two or three ply, or you can use styrofoam slabs. But I think the cardboard would be good enough. You need to fill the flask with liquid nitrogen before you put the ice cube in, so pick a big enough thermos bottle liner. Find the nitrogen by calling a welding gas supplier and asking; you'll probably need an adult's signature and supervision, plus they'll have to believe your container is sturdy and spillproof. Wear protection (goggles, gloves, apron). Otherwise, go with dry ice which is used to pack ice cream. This you can pack around the outside of the flask (thermos)be careful, extreme frostbite hazard. With enough layers of foil (to limit radiative transfer) and light casing/insulation (to limit conductivity) and starting with a low enough temperature, it shouldn't be much of a problem. Another approach is to start out with enough of a thermal mass. If your container is a BIG chunk of ice frozen VERY cold with a hole bored into it and then insulated (styrofoam or cardboard and foil, layered) it should easily last a week. Depending on how big and how cold, that sucker could keep it frozen for a month. Whatever you do, even the lightest, best insulated container you can come up with will have to be pre-cooled. Dry ice is probably the easiest way.
keep it in the freezer lololol
I guess my first question is whether or not your son is in special education. If he is, I would discuss the issues with his teacher, who may want to work on helping him express himself correctly. I see the incident with the knife more as part of his social disability in that he probably does not know what other people will think about his swinging a knife around. You have to teach him about the appropriate behavior every time he has an incident like this. It is just like learning to read, it needs to be taught. They just don't get it. Autism is a communication as well as a social disorder. Autistic kids usually get angry when they are unable to get their needs met because of the disorder. Many children require direct instruction in handling their emotions, using pictures if possible. I am currently working with a high functioning, autistic 6 year old who has tantrums.I showed her a number of different pictures of ways to handle anger without getting in trouble, such as asking for time alone, breathing and counting etc. I also wrote her a story about what happened when a kid tantrummed. She chose 3 different methods that she would like to use when angry and I made up three pictures of the one she chose. Then I taught her each of the methods and finally, gave her and her teacher the picture prompts for when she was angry. Visuals are the key. Autistic people are strongly visually oriented. Also, have your family rent the movie about Temple Grandin's life. It will enlighten everyone, including your son and yourself, about what it means to be autistic.
