The use of electric blankets is not recommended in the 4th month of pregnancy. Electric blankets are potentially dangerous to both pregnant women and fetus, with a certain probability of causing miscarriage, dry skin, constipation, etc. Meanwhile, it may induce fetal hypoxia, malformation, etc., which will affect the growth and development of the fetus. Electric blankets can produce electromagnetic fields, producing a certain amount of radiation, absorbed by pregnant women may increase the probability of miscarriage, and long-term use of pregnant women water loss, dry skin, constipation, agitation, etc., is not conducive to the health of pregnancy life. At the same time, in the long-term high temperature state, pregnant women metabolism is in a more active state, fetal movement can be frequent, easily triggered by intrauterine fetal hypoxia, slow growth. Electromagnetic fields can affect fetal development, especially the normal growth of fetal brain and nerves, resulting in structural and functional abnormalities and fetal developmental deformities. In order to keep warm, pregnant women can put hot water bags in the method of sleeping at the feet to warm up, pay attention to the temperature should not be too high, to prevent scalding the skin, triggering infections, or turn on the indoor air conditioning, to maintain a suitable temperature indoors. Pregnant women need to replenish water in a timely manner when the ambient temperature is raised to avoid the evaporation of water due to warming and discomfort.