Choose cotton. Save the ooh-la-la satin, silk, or polyester sheets for cooler nights. Light-colored bed linens made of lightweight cotton (Egyptian or otherwise) are breathable and excellent for promoting ventilation and airflow in the bedroom. Get cold comfort. Here’s a four-seasons tip for keeping utilities charges down: Buy a hot water bottle. In winter, fill it with boiling water for toasty toes without cranking the thermostat. During summer, stick it in the freezer to create a bed-friendly ice pack. Be creative. If you thought fans are just for blowing hot air around, think again! Point box fans out the windows…