If they don't pat you down before the test you can reheat the quick fix everyday, rubber band a heat pad to it (you can get additional ones at most stores) and just keep it in your pocket. If you are going to be patted down, you can keep it under your balls, but since I don't have balls, I can't tell you how comfy that is.....
One more time. Collectors are not authorized to touch you in any manner. Doing so constitutes groping and is against the law! Collectors can direct you to remove jackets and empty your pockets, but they cannot lay a hand on you.
There are regulations and protocols that the collectors have to follow. Any deviation from the regs, or in particular, violation of a donors civil rights can result in serious legal consequences for the facility, in which the aggrieved donor be entitled to civil remedy.

Know your rights.