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One of the chief complaints among memory foam mattress owners is that their beds sleep too hot. Memory foam retains more body heat than other mattress materials, causing some sleepers to become uncomfortably warm or hot during the night. This can decrease their quality of sleep and leave them feeling poorly rested when morning comes. Although you cannot change the temperature of memory foam or change how much body heat it retains, you may be able to optimize your sleep surface by using a mattress pad or topper, investing in sheets and pillows designed to keep you cool, and adjusting the temperature in your bedroom. Read on to learn more.
In addition to mattress pads and toppers, sheets, and pillows, sleepers can cool off at night by maintaining a steady temperature in their bedroom. Here are a few tips for keeping the heat down while you sleep:
The terms ‘mattress pad’ (or ‘mattress protector’) and ‘mattress topper’ are often used interchangeably, but these two items essentially serve different functions. A pad or protector is a thin layer that acts as a barrier between the sleeper and the mattress. A topper, on the other hand, is designed to add several inches to the sleep surface of the mattress; as a result, a topper is by definition much thicker than a pad or protector. Generally speaking, toppers are also much more expensive than pads or protectors.
Some pads and toppers have elasticized edges that can be tucked over the mattress edges like a fitted sheet, while others are non-fitted. Pads and toppers essentially serve the same function and the terms are often used interchangeably, but toppers are by definition thicker than pads. Many sleepers claim that the most comfortable configuration consists of a mattress pad on top of the topper.
Pads and toppers are relatively inexpensive, and often quite effective at cooling down a sleep surface. Pads and toppers made of natural fibers, such as cotton and wool, are generally considered the best choice because they are soft and breathable. Toppers stuffed with natural down or feathers can also create a cooler sleeping surface — though this material may be too soft for some.
Latex toppers are widely available as well, but a significant number of sleepers claim that latex traps heat to some extent and creates uncomfortable sleeping conditions. Similar complaints are associated with some waterproof toppers.
Most memory foam mattresses are constructed with solid layers of memory foam and polyfoam, which limits breathability and restricts airflow. The bedframe you choose can either help or hinder this. Wood and metal frames with evenly spaced slats improve airflow beneath the mattress, which can make the bed feel cooler. Solid, slatless frames often have the opposite effect.
It’s important to note that, according to mattress warranties, bedframe slats cannot be spaced too far apart. Otherwise the mattress will sag through the slats, creating sinkage and indentations in the sleep surface. In most cases, your mattress warranty will be voided if damage occurs due to improperly slatted frames.
The right sheets can cool off your bed to a considerable degree. Many sleepers have a positive experience with moisture-wicking sheets, which are designed to absorb sweat and reduce body heat retention. Additionally, sheets made of high-quality cotton (such as long-staple Egyptian or Peruvian pima cotton) are also linked to sleeping cooler, as are sheets woven with natural bamboo fibers. In terms of thread count, the top-rated sheets for sleeping cool typically range from 250 to 400 — though it’s important to remember that the fabric itself is more important to sleeping cool than the thread count.
Fitted sheets are usually the best choice because they cover the entire mattress, but it’s important to make sure the measurements match; if the sheets come loose in the middle of the night, then you may wake up with no barrier between your body and the memory foam surface.
Pillows can improve sleep conditions by cooling off the head, which in turn can lower overall body temperature. Pillows with natural materials like bamboo, buckwheat, feathers, and cotton tend to sleep the coolest. Latex also sleeps cool — but as mentioned above, latex can be a heat trap for some. Additionally, synthetic down made from polyester often sleeps cooler than natural down.
Memory foam pillows generally sleep the warmest, though pillows made of shredded memory foam tend to be cooler than one-piece pillows. Many companies offer pillows made of ‘gel memory foam’, claiming this material is infused with gel beads that allow it to sleep much cooler than standard memory foam. Some sleepers agree with these claims, but overall sleep ratings indicate that memory foam and gel memory foam retain similar levels of body heat and, as a result, sleep comparably hot.
If you tend to sleep warm or hot, then a memory foam mattress may not be the best option for you. However, if you already own a memory foam mattress, then consider investing in a pad or topper, using specialized sheets and pillows, and follow our tips for maintaining a comfortable bedroom temperature. These measures will usually suffice until it’s time to buy a new mattress.