Body wraps involve the application of heated towels or wraps to specific areas of the body to melt away fat and treat aches and pains. This procedure is not safe during pregnancy because there is no way to regulate how high body temperature will rise, or effectively judge how much heat is making its way to the fetus.
According to the American Congress of Obstetricians and Gynecologists, the core temperature of a pregnant woman should not exceed 102.2° F (38° C). Common every day activities like exercise can raise body temperature beyond this point, so you can imagine what wrapping the body in heated bandages for extended periods will do to body temperature.
Core body temperature should not be confused with basal body temperature (BBT). Basal body temperature is read first thing in the morning before a woman gets out of bed. Typically, in the first few weeks after conception, a rise in basal body temperature can also denote a miscarriage. Basal body temperature often reads between 97°F and 98° F.