Will these cooling protectors keep you cool while you're sleeping throughout the night? In theory, yes. Just note that if you have several layers of non-cooling fabrics between you and your cooling protector, you may not reap the all the benefits. Another thing to consider is that there are two sides to your body — the side on your sheet and protector and the other that faces up. If both your sheets and your protector have cooling technology but the blanket on top of you does not, that will affect your overall temperature.