With temperatures set to hit 34 ⁰C in parts of the UK today, the Society of Health Scientists’ Society of Physiology has some helpful advice to help keep you cool. But they also warned – cooling too quickly could be fatal.
1. Avoid all forms of heat, including exercise
Exercising in the heat increases muscle blood flow and the body’s core temperature, which puts additional stress on the body. The increased need for skin blood flow at high temperatures, especially if combined with dehydration, can impair muscle blood flow, reduce oxygen delivery to the muscles and lead to heat exhaustion. The heart also has to work harder to maintain circulation.
2. Stay hydrated
In hot weather, it is important to reduce the risk of dehydration. Hydration maintains good cardiovascular function and helps your body sweat. This is essential for maintaining normal body temperature. If you’re hydrated, your urine will be a pale straw color. If you’re not drinking enough fluids, your urine will darken as your kidneys store as much water as possible.
3. Wear sunscreen to avoid sunburn
Any exposed body parts, including earlobes, scalp, and lips, can burn. Sunburn affects skin circulation and sweating, thus limiting the body’s ability to dissipate heat. In addition, the UV radiation the skin absorbs from sunlight can also damage genetic material in skin cells, increasing a person’s risk of developing skin cancer.
4. Use a fan to cool yourself artificially
When we are hot, we sweat. Sweating helps us control our body temperature because when sweat evaporates into the air, it cools the skin. Fans speed up this evaporation process and increase convective cooling, helping us maintain our body temperature. You can further enhance evaporative cooling by wearing light and undressing and misting your body with water.
5. Immerse your hands in cold water
Our hands have a high surface area to mass ratio, and special blood vessels in the fingers have high blood flow at high temperatures, making them ideal areas for heat exchange with the environment. When hands are immersed in cold water, body heat is quickly lost, lowering body temperature.
Here is a short video summarizing these 5 points: https://we.tl/t-wm4bvskwyM
Why Trying to Cool Down Too Fast Can Be Deadly
With today’s hot weather, many may be tempted to jump into the ocean or open water to cool off. However, sudden immersion in cold water can be fatal. Mike Tipton, professor of human and applied physiology and director of the Physiological Society at the University of Portsmouth’s School of Sport, Health and Exercise Sciences, has been studying the body’s response to sudden immersion in cold water for the past 20 years.
“In today’s hot weather, many people may want to cool off in cold water. However, jumping into cold water (under 15 ⁰C) Can cause a “cold shock” response, including an involuntary gasp response, followed by uncontrolled hyperventilation. This reaction is very dangerous if you are in water, as 2-3 liters of gasp is larger than the amount of water needed to drown in the lungs (1-3 liters). “
We lose about 400 people a year to immersion-related accidental deaths, and drowning rates rise during heatwaves. Professor Tipton believes that many of these deaths could be avoided if people understood some basic physiology.
“Education = Survival. The more people learn about the cold shock response, the more they can do to protect themselves. During the first 90 seconds, we see the greatest physiological response to immersion in cold water. If you get into the water faster, the cold Shock response will be greater.
So if you have to get into the water, the secret to survival is to do it slowly or in part. If you accidentally or intentionally find yourself in cold water after a fall, resist the urge to roll or swim until the cold shock reaction passes. It’s important to relax and float to keep the water out of your airways until your breathing is back under control. Allowing your body time to adjust to the cold water reduces the risk of drowning. “
Learn more about cold water survival in this video:
