The normal values of heart rate for infants of all ages are as follows:
　　Heart rate of newborn infants: 120-140 beats/min
　　Heart rate of infants under 1 year old: 110-130 beats/min
　　Heart rate for infants 2-3 years of age: 100-120 beats/min
　　Heart rate for infants 4-7 years old: 80-100 beats/min
　　Heart rate for infants 8-12 years old: 70-90 beats/min

Changes in heart rate are related to a variety of factors such as eating, exercise, mood, sleep, and fever.
The faster heart rate of infants is mainly related to high metabolism and sympathetic excitability. The heart rate of infants is unstable and is easily affected by various internal and external factors, such as eating, activity, crying and fever. Therefore, the infant's heart rate should be measured during quiet hours. If the heart rate increases significantly and does not slow down during sleep, organic heart disease should be suspected. Go to the hospital for a thorough examination.

The normal values of respiration for infants of all ages are as follows:
Respiratory rate of newborn infants: 40-50 breaths/min
Respiratory rate of infants under 1 year old: 30-40 breaths/min
Respiratory rate for infants aged 2-3 years: 25-30 breaths/min
Respiratory rate for infants aged 4-7 years: 20-25 breaths/min
Respiratory rate for infants aged 8-12 years: 18-20 breaths/minute

Observe the baby's breathing movements to know whether the baby is sick or not in time.
2.1, Normal infant breathing when the lips are together, if the infant appears to open mouth breathing, nasal flapping, excluding the case of nasal congestion, it is a manifestation of the infant breathing faster.
2.2, Normal breathing is abnormal if there is a depression at the intercostal area or the acromion below the rib cage.
2.3, Baby's breathing is mainly abdominal breathing, if the baby's chest also follows the breathing, or the chest and abdomen rise and fall when breathing, these conditions are abnormal.
2.4, The baby breathing with adult voice, as if being wounded sigh, this is a symptom of illness. If the infant has these phenomena when breathing, especially when sleeping, the mother and father should take the baby to the hospital for examination in time.
One thing to note is that the infant's respiratory center is not yet well developed, so there will be irregularities in the breathing rhythm, with alternating deep and shallow breathing or uneven fast and slow breathing, especially after the baby falls asleep, these conditions are normal.

Measure body temperature is generally used in three areas, namely the oral cavity, armpit and anus.
The normal body temperature at the anus is between 36.5 ℃ and 37.5 ℃;
In the oral cavity, it is between 36.2℃ and 37.3℃;
In the armpit is between 35.9 ℃ ~ 37.2 ℃.
It is often said that the body temperature of infants under one year old is normal below 37.5℃. The reason is that the baby's brain control center of thermoregulation is not yet mature, that is, the ability to control body temperature is not strong enough, resulting in the baby's body temperature will be affected by the environmental temperature. In hot weather or wrapped too much, the body temperature will be mildly elevated, but should not exceed 37.5 ℃. In cold weather or cold air-conditioned rooms, the body temperature can be reduced to 36℃ or lower.

3.1, After measurement, if the temperature exceeds the normal range by more than 0.5℃, it is called fever. Not more than 38℃ is called low fever, and more than 39℃ is high fever.
3.2, Baby's body temperature is slightly higher than that of adults because of the unstable function of the thermoregulatory center and the high metabolism. The body temperature fluctuates throughout the day, with a low body temperature when quiet and a high body temperature when active, with the lowest body temperature in the morning from 2 to 6 and the highest in the afternoon from 2 to 8, fluctuating by about 0.6℃.
3.3, Body temperature "low", in fact, is also normal, but the premise is stable, that is, as long as it can be stable in this range there is no problem, the baby's body temperature by the body inside and outside the influence of various factors will be self-regulation, but you must pay attention to the baby's warmth, so as to avoid the baby cold fever.

4.1, The appropriate ambient temperature is 24℃-26℃.
The infant's thermoregulatory center is very unstable, and changes in the ambient temperature have a relatively large impact on the infant's body temperature. If the change in ambient temperature exceeds the infant's ability to regulate itself, it may cause cold damage or fever. Therefore, the appropriate relative indoor temperature is very important for infants.

4.2. The appropriate ambient humidity is 45%-70%.
Infant's room, indoor relative humidity is appropriate at about 50%. Humidity is too small, it will accelerate the evaporation of infant water, resulting in dehydration, dry respiratory mucosa, reducing the ability of the respiratory tract to resist pathogenic bacteria. Too much humidity is conducive to the reproduction of some pathogenic bacteria, especially mold, increasing the risk of infants being infected.
High humidity does not require special humidification, if the humidity is greater than 70%, you can use a dehumidifier to properly reduce the humidity.

It is the sudden death of an infant under 1 year of age with a clinical history that cannot be explained even after a thorough investigation including a complete autopsy, death scene examination and review.
The word "SIDS" may sound scary, and the death of an infant is always heartbreaking. However, there are many ways you can reduce his or her risk while providing the best care for your baby.
The best way to reduce the risk of SIDS is to always keep your baby on his or her back at all sleep times in a separate sleep area designed for babies without soft objects, toys or loose bedding. Studies have shown that the risk of SIDS is lowest in the supine position. And infants who sleep on their backs are less likely to have fevers, nasal congestion and ear infections. The supine position makes it easier for infants to look around the room and move their arms and legs.

Babies who sleep on their backs do not suffocate.
Healthy infants naturally swallow or cough up liquids - a reflex that all people have. Babies can actually clear these fluids better when they sleep on their backs because the opening of the lungs is positioned relative to the opening of the stomach. There is no increase in choking or similar problems in infants who sleep on their backs. When the infant is in the supine position, the trachea (the tube leading to the lungs) is located on top of the esophagus (the tube leading to the stomach). Anything that refluxes or regurgitates from the stomach through the esophagus must resist gravity to enter the trachea and cause asphyxia. When an infant sleeps on his or her back, this fluid flows out of the esophagus and collects at the opening of the trachea, making asphyxiation more likely.

Fatal asphyxia is very rare, unless it is related to a medical condition. Fatal asphyxiation deaths have not increased since back sleep recommendations began. Of the few reported cases of fatal asphyxia, most were infants sleeping on their backs.
Parents and caregivers should put infants to sleep on their backs, even if they appear to be more uncomfortable or sleep more lightly than when they are prone. Infants who wake frequently during the night are actually normal and should not be considered "poor sleepers. Some babies don't like to sleep on their backs at first, but most get used to it quickly. The sooner you start putting your baby to sleep on his or her back, the faster your baby will adapt to the position.

Remember: babies sleep best on their backs, and it's important that they sleep every time!