A warm blanket is the ideal sleep aid for a freezing winter night. The right blanket can warm your bones but the wrong one can affect your sleep. I asked experts for advice on picking the perfect blanket for a good night's sleep. Here's what they told me. When it comes to sleep temperature, experts recommend following the principle: not too cold, not too hot, but just right. "People seem to sleep best at temperature between 62 and 70 degrees F," says Dr. Alice Hoagland. When the surrounding temperature falls too low, it can _ you from sleep. A good blanket helps drive the coldness away. At the other extreme, overheating yourself can affect your sleep as well. "Core body temperature typically drops during the first four hour's of sleep," says Dr. Hoagland. This decline in body temperature helps you fall asleep and stay asleep. "In medical care, weighted blankets are one of our most powerful tools for helping people who are anxious, upset, and possibly losing control," says Dr. Karen Moore. These special blankets are filled with weighted pellets. Weighted blankets are also marketed for general use as an aid to sleep and relaxation. Like a firm hug, weighted blankets help us feel safe." This is the reason why many people like to sleep under a blanket even in summer. "If you want to try this type of blanket, the best weight depends on your body size and personal preference. However, 15 to 30 pounds is typical for adults," Moor says. She adds that weighted blankets are not recommended for those recovering from surgery. "People can also have serious preferences for a particular blanket," says Dr. Hoagland. "Regularly using a favorite blanket for sleep can help to develop a conditioned response so that sleep is quicker." In fact, many sleep centers ask patients to bring their own blanket and pillow from home, which helps them fall asleep more easily. The author wrote the passage mainly to tell us   _  .
the importance of blankets how to choose the perfect blanket different materials used to make blankets the history and usage of blankets
Question: A warm blanket is the ideal sleep aid for a freezing winter night. The right blanket can warm your bones but the wrong one can affect your sleep. I asked experts for advice on picking the perfect blanket for a good night's sleep. Here's what they told me. When it comes to sleep temperature, experts recommend following the principle: not too cold, not too hot, but just right. "People seem to sleep best at temperature between 62 and 70 degrees F," says Dr. Alice Hoagland. When the surrounding temperature falls too low, it can _ you from sleep. A good blanket helps drive the coldness away. At the other extreme, overheating yourself can affect your sleep as well. "Core body temperature typically drops during the first four hour's of sleep," says Dr. Hoagland. This decline in body temperature helps you fall asleep and stay asleep. "In medical care, weighted blankets are one of our most powerful tools for helping people who are anxious, upset, and possibly losing control," says Dr. Karen Moore. These special blankets are filled with weighted pellets. Weighted blankets are also marketed for general use as an aid to sleep and relaxation. Like a firm hug, weighted blankets help us feel safe." This is the reason why many people like to sleep under a blanket even in summer. "If you want to try this type of blanket, the best weight depends on your body size and personal preference. However, 15 to 30 pounds is typical for adults," Moor says. She adds that weighted blankets are not recommended for those recovering from surgery. "People can also have serious preferences for a particular blanket," says Dr. Hoagland. "Regularly using a favorite blanket for sleep can help to develop a conditioned response so that sleep is quicker." In fact, many sleep centers ask patients to bring their own blanket and pillow from home, which helps them fall asleep more easily. The author wrote the passage mainly to tell us   _  .
A. the importance of blankets
B. how to choose the perfect blanket
C. different materials used to make blankets
D. the history and usage of blankets
Answer: