We light up the skies with spectacular fireworks across our nation in celebration of the Fourth of July, our country’s birthday.
On that day in 1776, the members of the Second Continental Congress met in Philadelphia to adopt the final draft of the Declaration of Independence. John Adams predicted that the anniversary of the day “will be celebrated with pomp and parade … bonfires and illuminations from one end of this continent to the other.” He was so right!
As we get ready for our parades, festivals and get-togethers, there is an elephant in the room: the heat. Recently, it’s been so hot that by the time I get home from the grocery store, my loaf of bread is toast.
OK, that might be overstating things, but here is Dr. Nina’s What You Need to Know about staying safe in the heat on the Fourth of July and throughout the summer.
How do we “chill out?” Our body temperature normally remains within a narrow range – 98.6 degrees Fahrenheit, plus or minus 1 degree. Our skin plays a pivotal role when it comes to keeping us cool. As our internal temperature rises, blood flow automatically increases to the upper layers of the skin so heat can dissipate into the environment. Concurrently, water diffuses through the skin (aka perspiration, sweating), and heat is removed from the body when it evaporates.
Can I get a chemistry and physics refresher course? We all know that a hot cup of coffee will cool over time (heat dissipates into the environment), but will never become cooler than room temperature. Heat is a form of energy and always flows from high temperature to low temperature, a phenomenon known as equilibrium. When the temperatures between our body and the environment are equal, there is no net flow of heat. Consequently, hot weather makes it difficult or impossible for us to cool down.
What can happen if we cannot cool down? We can experience heat-related illnesses ranging from rashes to heat cramps, exhaustion and stroke. Heat cramps are painful spasms in our legs and abdomen that are accompanied by heavy sweating. Heat exhaustion describes confusion, dizziness, fainting, headache and vomiting. This can progress to heat stroke, a medical emergency, where our body’s temperature increases to greater than 105 degrees and can literally fry our brain.
How do we keep safe with sky-high temperatures?
•Limit strenuous activities to the morning and evening hours, when it is cooler.
•Pretend we are fish. Not only does drinking fluids cool us down, it is necessary to replace what is lost from sweating and perspiration. The key is to drink consistently throughout the day, not just when we feel thirsty. If we are engaging in strenuous activities, set a goal to drink two to four 8-ounce glasses of fluid every hour. Additionally, we need to be aware that alcoholic, caffeinated and sugary drinks increase urination and, hence, cause fluid loss.
•Dress for success. Lightweight clothing allows our body to dissipate heat instead of insulating it. Light-colored clothing reflects heat whereas darker colors absorb it.
•Don’t get burnt. In addition to increasing our risk for skin cancer, sunburn prevents heat dissipation. The red that we see is actually superficial broken blood vessels that will decrease blood flow to the skin’s surface.
•Know who is at risk. Young children (their bodies heat up three to five times faster than an adult’s), people aged 65 and older or those with chronic illness (heart disease, hypertension) are at greater risk for heat-related illness.
•Retreat to air-conditioned areas whenever possible.
•Hot cars. Heatstroke is the leading cause of non-crash, vehicle-related deaths for children. Temperatures inside a car can increase, putting anyone in danger – especially children. When buckling our children in, make sure that the belt buckles are not too hot, especially when the car has been parked in the heat.
In July of 1776, there were an estimated 2.5 million people in our newly found nation. Today, we have an estimated population of 316 million. It would be accurate to state that we have come a long way. Let’s stay cool and safe as we celebrate our “Life, liberty and pursuit of happiness.”