A hickey is put there to show up! It's a mark of I-Was-Here. Why else did you get a hickey on your neck? But let's assume that some wild hickey attacker got to you and now you have to hide the evidence. Again, it's a bruise. It won't just vanish with warm water or cold water or lukewarm water. You can get make-up concealer and try that, to cover it while it fades away naturally. Wear turtlenecks or scarves. If you tend to be a really slow healer, take vitamins and eat healthy food so your body has half a chance of healing up well. Stand in dark corners
