How Newton’s Law of Cooling Affects Babywearers

Well, not really. But I liked how the title sounded. What this post is really about is preventing heat-related illness or injury while babywearing in warm weather. Heat-related illness claims about 334 lives per year.   Heat-related deaths are less common in tropical areas and more common with sudden temperature changes.⁶

Heat exhaustion results from dehydration or poor heat acclimation (more common in the early summer months). The child may be tired, dizzy, anxious and may exhibit nausea and vomiting. Treat by moving to a cool space, rest and have the child drink cool water. ³

Heatstroke is a medical emergency. This happens when someone’s thermoregulatory mechanisms fail and the internal body temperature rises to greater than 104 degrees F. Symptoms include weakness, confusion, loss of consciousness and seizures. The child may be unable to sweat. Treatment includes activating emergency response by dialing 911, removing clothes, apply cool water to the body, and using fans to encourage convective heat loss. People who have experienced heatstroke remain at a higher risk for reoccurrence later in life. Subsequent heatstroke can put the patient at even higher risk of injury. ³

Certain populations are at higher risk of heatstroke:

1. Children younger than 4 and adults older than 65
2. People with a diagnosis of cystic fibrosis, heart disease or lung disease
3. People who take certain medications such as beta-blockers, sedatives, antipsychotics, diuretics (water pills), medications to treat Parkinson’s (inhibits sweating),⁵ and stimulants (ADHD medications)⁴.
4. BMI greater than 25
5. People with sunburns ⁵

What are some effective ways to dissipate body heat when babywearing in warm weather? Call your 5^th grade science teacher.

The THREE MODES OF HEAT TRANSFER

Evaporative – As perspiration or moisture on the skin evaporates into the air, the body is cooled. Stand in cool misters. Drip water on your head and on baby’s head. Keep yourself and your baby well hydrated, but do not overhydrate. Drink before you’re thirsty, but drink to satisfaction. Humidity plays an important factor in the body’s ability to cool itself through perspiration.

Conductive – Being in contact with cooler surfaces. The area of the human body and the thermal conductivity of the air surrounding the body. Unclothed skin cools more easily than clothed skin. Stay in the shade. Adult bodies cool more easily than a child’s. Monitor behavior closely.

Convective – The movement of air or water over the skin. Use fans, stand in a breeze. Air motion will strip away the heated layer surrounding the skin and increase the transfer of heat to the air. Movement of water over the skin can cool someone 25 times faster than air. Sit in a puddle, put your legs in the pool, etc. Conduction and convection work closely together.

Radiation – People with higher metabolisms generate higher body temperatures (young people). People with higher percentages of adipose tissue (fatty tissues) may not radiate heat as well and are at higher risk of overheating and require more water to stay hydrated. People who are too cold will shiver (physical activity) to gain heat. Reducing physical activity in the heat will help you stay cooler.^{1, 2}

^8.

Infants and children are at higher risk for heat-related illness (King, 1995 pg. 1839). They create more body heat due to higher metabolism. Their body mass makes it easier for heat to transfer heat from the environment to their body. It takes longer for children to acclimate to hot conditions and children do not have the sweating capacity that adults do.

In humid conditions, the evaporative effects of perspiration are blunted and the body has a reduced capacity to cool itself. Monitor your area’s “heat index” as well as the temperature to evaluate risk of heat injury.⁷

References:

1. http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/bodcon.html
2. http://www.beyondcoldwaterbootcamp.com/mechanisms-of-heat-loss
3. King, Patricia L., (1995). The child with musculoskeletal or articular dysfunction. In Donna L. Wong & David Wilson (5^th), Whaley & Wong’s Nursing Care of Infants and Children (1794-1867). St. Louis: Mosby, 1995
4. http://www.mayoclinic.org/diseases-conditions/heat-stroke/basics/risk-factors/con-20032814
5. http://emergency.cdc.gov/disasters/extremeheat/faq.asp
6. http://emedicine.medscape.com/article/166320-overview#a6
7. http://www.srh.noaa.gov/ama/?n=heatindex
8. http://www.drcruzan.com/HeatTransfer.html