Exposure to heat in hot weather and activities like working out can cause your body temperature to go up. Your normal body temperature is 98.6 degrees Fahrenheit, or 37 degrees Celsius. Hyperthermia occurs when you have a high temperature (102 degrees Fahrenheit, or 38.9 degrees Celsius) for an extended period of time without an actual fever. When you are expecting there is a concern of an elevated core temperature causing neural tube defects, spontaneous abortion, and other abnormalities. There are cautions you should take when practicing Bikram yoga, going in a hot tub or sauna, and even taking a hot bath. Learn about heat exposure and how to make sure you and your baby stay safe and do not overheat.