What special bedding can be filled with air or fluid to regulate a patient's body temperature?

The correct answer is thermal blankets, which are specifically designed to manage and regulate a patient's body temperature effectively. They work by utilizing air or fluid that can either provide warmth or promote cooling, depending on the patient's needs.

Thermal blankets are often used in medical settings to help maintain normothermia in patients, especially those undergoing surgery or suffering from conditions that affect their temperature regulation. The ability to adjust temperature through the fluid or air filling allows for precise control, making them a valuable resource for medical professionals in ensuring patient comfort and safety.

The other options listed serve different purposes. Heating pads provide local heat to alleviate pain but do not regulate temperature comprehensively. Electric blankets can provide warmth, but they lack the fluid or air management capability that allows for temperature regulation. Sleeping bags are designed primarily for insulation and warmth in outdoor or camping scenarios, not for the specific medical context of temperature control. Thus, thermal blankets stand out because of their specialized design and functionality for health care applications.