Guys,

Check out this heat pack you can make with stuff you have at home... Take a white sock (any color damn it, but you know the big socks? that's what you will need) and fill it half way or a little bit less with rice (doesn't matter, white or brown) then make a knot on the open end. Throw that puppy in the microwave for about 40 seconds and check it out man. Awesome heat pack.

Use it for the after injection site or if you have an aching muscle or something just apply it. It will stay warm for a long time and you can use this thing over and over. It is cheap and easy to make. Try it and get back to me.

Note: You will have to play with the time on the micro. For mine 40 seconds is just right. If I do 50 it's just way too hot and I have to let it cool off for a few minutes.

my parents going to think im crazy for this ^ ^

and it's also a perfect breeding ground for germs...

Just use a normal rubber heat pack that you can sterilize... it's like 3-5 bucks...