What Temperature Should I Use to Prepare Formula?
Medically reviewed by Dr. Rachel Kim, MD, RDN · Pediatric Nutrition Specialist
Content reviewed against published WHO, CDC guidelines
Last reviewed:
Feeding challenges are one of the most common concerns new parents face. When it comes to what temperature should i use to prepare formula, here is what the guidelines recommend.
The short answer
The WHO recommends using water that has been boiled and cooled to no less than 158F (70C) to prepare powdered formula to kill any bacteria like Cronobacter that may be present in the powder. However, many families in the US use room temperature or warm water. The CDC recommends using water from a safe source. Always follow the mixing instructions on your formula can exactly.
Key takeaways
- The WHO recommends using water that has been boiled and cooled to no less than 158F (70C) to prepare powdered formula to kill any bacteria like Cronobacter that may be present in the powder. However, many families in the US use room temperature or warm water. The CDC recommends using water from a safe source. Always follow the mixing instructions on your formula can exactly.
- Usually normal when: You prepare formula with water from a safe source following package directions
- Call your doctor if: Baby develops symptoms of foodborne illness such as vomiting, diarrhea, and fever after a formula feed
- Varies by age — see the age-by-age breakdown below
“The AAP recommends exclusive breastfeeding for approximately 6 months after birth. Furthermore, the AAP supports continued breastfeeding, along with appropriate complementary foods introduced at about 6 months, for 2 years or beyond.”
This is one of the most common questions parents ask. Searching for answers means you care.
What Parents Should Know
According to WHO, CDC guidelines, the WHO recommends using water that has been boiled and cooled to no less than 158F (70C) to prepare powdered formula to kill any bacteria like Cronobacter that may be present in the powder. However, many families in the US use room temperature or warm water. The CDC recommends using water from a safe source. Always follow the mixing instructions on your formula can exactly. At 0-3 months, newborns are most vulnerable to bacteria in formula. Using boiled water cooled to 70C (158F) provides the best safety margin. Let the formula cool to body temperature before feeding. Always test on your wrist. For premature or immunocompromised babies, this step is especially important. It is generally considered normal when you prepare formula with water from a safe source following package directions. However, you should contact your pediatrician promptly if baby develops symptoms of foodborne illness such as vomiting, diarrhea, and fever after a formula feed.
Normal vs. Concerning
By Age
What to expect by age
0-3 months
Newborns are most vulnerable to bacteria in formula. Using boiled water cooled to 70C (158F) provides the best safety margin. Let the formula cool to body temperature before feeding. Always test on your wrist. For premature or immunocompromised babies, this step is especially important.
4-6 months
Continue safe preparation practices. If using a formula pitcher to make larger batches, refrigerate immediately and use within 24 hours. Shake or stir well before serving.
6-9 months
The same preparation guidelines apply. As baby starts solids, formula remains important and should be prepared safely.
9-12 months
Some babies at this age prefer formula at different temperatures. It is safe to serve formula cold, at room temperature, or warm as long as it was prepared safely.
12-24 months
If still using formula, the same preparation rules apply. Many toddlers transition to whole milk around 12 months.
What to Tell Your Pediatrician
- Describe when you first noticed what temperature should i use to prepare formula and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if you are unsure about your water quality and whether it is safe for formula.
- Mention if you want guidance on the safest preparation method for your baby.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- You prepare formula with water from a safe source following package directions
- You test formula temperature on your wrist before feeding
- You discard formula that has been at room temperature for more than 2 hours
- You are unsure about your water quality and whether it is safe for formula
- You want guidance on the safest preparation method for your baby
- Baby has frequent digestive issues and you wonder if preparation method could be a factor
- Baby develops symptoms of foodborne illness such as vomiting, diarrhea, and fever after a formula feed
- There is a formula recall and you have the affected product
What You Can Do at Home
- Keep track of when you notice what temperature should i use to prepare formula — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that you prepare formula with water from a safe source following package directions — this is generally within the range of normal.
- At 0-3 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Offer feeding in a calm, distraction-free environment. Avoid forcing or pressuring your baby to eat.
- While monitoring at home, seek immediate care if baby develops symptoms of foodborne illness such as vomiting, diarrhea, and fever after a formula feed.
Related Conditions
How to Prepare Formula Safely
Safe formula preparation involves using clean water, following the manufacturer's mixing instructions exactly, and practicing good hygiene with bottles and equipment. Using too much or too little water can be dangerous for your baby. The CDC recommends using water from a safe source and, for babies under 3 months or those who are immunocompromised, boiling and cooling the water before mixing.
Formula Storage Guidelines
Prepared infant formula can be stored in the refrigerator for up to 24 hours and should be used within two hours once at room temperature or within one hour after a feeding has begun. Opened containers of powdered formula should be used within one month and kept in a cool, dry place. Following these guidelines helps prevent bacterial growth that could make your baby sick.
Mixing Formula: Getting the Concentration Right
Getting the concentration of formula exactly right is essential for your baby's safety and nutrition. Adding too much water dilutes the nutrients and can cause dangerous electrolyte imbalances, while adding too little water makes the formula too concentrated and can strain your baby's kidneys. Always follow the manufacturer's instructions on the label and use the scoop that comes with that specific formula.
Related Resources
Milestone Checklists by Age
Track your baby's developmental milestones from birth to 5 years with age-specific checklists.
Feeding & Nutrition Guide
Complete guide to breastfeeding, formula feeding, and solid food introduction.
Month-by-Month Development
Detailed monthly development guides from birth through 24 months.
When to Call the Doctor
General guide on when to call the pediatrician, visit urgent care, or go to the ER.
Frequently asked questions
Is what temperature should i use to prepare formula normal?
When should I call the doctor about what temperature should i use to prepare formula?
When is what temperature should i use to prepare formula normal?
What causes what temperature should i use to prepare formula?
What should I mention to my pediatrician about what temperature should i use to prepare formula?
Is what temperature should i use to prepare formula normal at 0-3 months?
Is what temperature should i use to prepare formula normal at 4-6 months?
Should I go to the ER for what temperature should i use to prepare formula?
Does what temperature should i use to prepare formula go away on its own?
References
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss What Temperature Should I Use to Prepare Formula?.
Things to mention
- Describe when you first noticed what temperature should i use to prepare formula and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if you are unsure about your water quality and whether it is safe for formula.
- Mention if you want guidance on the safest preparation method for your baby.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- You are unsure about your water quality and whether it is safe for formula
- You want guidance on the safest preparation method for your baby
- Baby has frequent digestive issues and you wonder if preparation method could be a factor
Urgent signs to report immediately
- Baby develops symptoms of foodborne illness such as vomiting, diarrhea, and fever after a formula feed
- There is a formula recall and you have the affected product
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members
Related Resources
Bottom line
Most cases of what temperature should i use to prepare formula are normal. Talk to your pediatrician if baby develops symptoms of foodborne illness such as vomiting, diarrhea, and fever after a formula feed.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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Related Feeding Concerns
How to Prepare Formula Safely
Safe formula preparation involves using clean water, following the manufacturer's mixing instructions exactly, and practicing good hygiene with bottles and equipment. Using too much or too little water can be dangerous for your baby. The CDC recommends using water from a safe source and, for babies under 3 months or those who are immunocompromised, boiling and cooling the water before mixing.
Formula Storage Guidelines
Prepared infant formula can be stored in the refrigerator for up to 24 hours and should be used within two hours once at room temperature or within one hour after a feeding has begun. Opened containers of powdered formula should be used within one month and kept in a cool, dry place. Following these guidelines helps prevent bacterial growth that could make your baby sick.
Mixing Formula: Getting the Concentration Right
Getting the concentration of formula exactly right is essential for your baby's safety and nutrition. Adding too much water dilutes the nutrients and can cause dangerous electrolyte imbalances, while adding too little water makes the formula too concentrated and can strain your baby's kidneys. Always follow the manufacturer's instructions on the label and use the scoop that comes with that specific formula.
When to Introduce Allergens to Baby
Current guidelines recommend introducing common allergens (peanut, egg, cow's milk products, tree nuts, wheat, soy, fish, shellfish, sesame) starting around 4-6 months when your baby is developmentally ready for solids. The landmark LEAP study showed that early introduction of peanuts (by 4-6 months) reduced peanut allergy risk by 80% in high-risk infants. Do not delay allergens - the old advice to wait until 1-3 years has been reversed because early exposure actually prevents allergies.
I'm Worried My Baby Is Aspirating During Feeds
Aspiration means liquid or food enters the airway instead of the stomach. Occasional coughing during feeds is common and does not usually indicate aspiration. True aspiration is less common and may present as recurrent respiratory infections, a wet or gurgly voice after feeds, or chronic cough. If you are concerned, a swallow study can provide a definitive answer.
When Does My Baby Need Amino Acid Formula?
Amino acid-based formulas (also called elemental formulas) are prescribed for babies with severe cow's milk protein allergy, multiple food protein intolerances, or conditions like eosinophilic esophagitis who cannot tolerate standard or extensively hydrolyzed formulas. They are the most hypoallergenic formula available because the proteins are broken down into individual amino acids, making allergic reactions virtually impossible.