there should be an exp date on the back, I hear they are good for 6 years.
Stacks62 Reviewed by Stacks62 on . How reliable is the heat pack? I'm just curious at how reliable a heat pack is? I have to drive and wait about 1 hour after I microwave synthetic urine. I plan on taping it to my inner thigh and have the heat pack against it also taped. My only problem is that where I'm going to take the test is an hour drive (plus however long it is to wait to be tested). How efficient is the heat pack on keeping the temperature above 90 degrees? I don't want to get there and have it below and be all "well shit..." Rating: 5