Hot summer nights can make it difficult to fall asleep, especially if your home is not air conditioned. If you can keep your head cool, it can help the entire body feel cool. Your pillow may absorb some of the body heat, and retain it for a while--and this is definitely not desirable for a hot summer night. There are easy, inexpensive ways to keep any pillow cool all through those unpleasantly warm nights.
Place a large freezer gel pack--the soft, flexible kind used in first aid or for lunch coolers--in your freezer several hours before bedtime. If you don't have a large gel pack, you can make one from home ingredients. Nursesnotebook.com offers several suggestions, including this one: mix rubbing alcohol with water in a sturdy freezer bag. The dilution should be 4 parts water to 1 part alcohol. This will freeze into a slushy mix.
Place your pillow in a large plastic bag and place it in the freezer at least an hour before bedtime. You can do this more than an hour before retiring, but you shouldn't wait too long or it won't get as cold.
Remove your pillow from the freezer. Remove the gel pack from the freezer, as well, and stick it in your pillow beneath the pillow case. This should keep your pillow cold all night, and you can repeat the process each day, as necessary.
If the gel pack makes the pillow too cold, either turn the pillow over (so the pack side is against the mattress) or wrap the pack in a towel before placing it in your pillow. Wetting your hair before bed will also help your head stay cooler through the night.