Learning how to beat the heat during scorching summer weather.
As we face increasingly hot summers, understanding how to avoid the health dangers associated with high temperatures has become more important than ever. Here are some tips to help you stay cool in scorching weather.
1. Stay hydrated
Water is vital to keep you both healthy and cool. When you are dehydrated,[1] the amount of blood flowing through your cardiovascular system decreases, which makes your heart work harder, increasing your core body temperature. On a regular day, most healthy adults need between 1/2 and 3/4 of a gallon (2-3 liters) of water. In hot weather, you’ll need to drink more than you usually would. You should start with plain water and switch to drinks containing electrolytes like coconut water[2] and Gatorade later in the day to replenish the ones you’ve sweated out. If you fancy something colder, flavored ice cubes from fruit and herbs[3] or juices[4] will both add pizzazz to your drink and replenish your electrolytes.[5]
Hot drinks can also cool you down if you are already feeling hot. This may seem counterintuitive, and indeed, they will initially make you feel hotter, but that will make you sweat, which will lower your body temperature.[6] There’s just one caveat: the sweat needs to be able to evaporate quickly,[7] so this trick will not work if hot temperatures are paired with high humidity, or if you’re wearing a lot of clothing. Avoid caffeine, which causes vasoconstriction,[8] the constriction of blood vessels that warms the body. Trying to cool down with an iced coffee or an energy drink may temporarily cool you, but then the warming effect of caffeine will kick in. Finally, ditch the booze: alcohol is a diuretic[9] that causes you to urinate more and can leave you severely dehydrated.
2. Eat wisely
Eating can increase your core temperature as your body works to digest and metabolize your meal.[10] The more calories you eat, the hotter your body will get. Therefore, try to eat light; salads will keep you cooler and also have the benefit of not requiring you to slave over a hot stove to make them. Salads also often contain foods that have a high water content,[11] like cucumber, lettuce, and tomatoes. These foods both replenish your electrolytes and help you stay hydrated.
If you’re thinking that you would prefer your cold food in the form of ice cream, think again. Sadly, eating this frozen treat may actually make you hotter as your body works to digest the calories. Sorbets[12] are a better alternative. At the other end of the flavor scale, spicy foods,[13] like hot drinks, also cool us down. This is because spicy foods excite thermoreceptors in the skin that normally respond to heat, triggering the usual responses — vasodilation, flushing, and sweating — which help you cool off. Spices can also curb your appetite[14] and help you to eat lighter meals.
3. Use a fan — sometimes
Fans cool us down by speeding up the evaporation of sweat from our bodies, but they do not work equally well in all situations. Fans can actually make you feel worse in dry heat. Sweat evaporates without any extra help when it’s very hot and dry, so, under those conditions, fans merely blow suffocating air around the room, creating an environment similar to a convection oven and causing you to dehydrate. And the fan’s motor can make the room even hotter. Both the U.S. Environmental Protection Agency[15] and the World Health Organization[16] advise against using fans in temperatures above the mid to high 90sºF (above 35ºC).
However, a 2019 study[17] found that fans do provide relief when conditions are humid. You can enhance the cooling feeling by misting your body with water or by putting a preferably metal or glass bowl of ice cubes in front of the fan.[18]
4. Be clever with water
Water is not just for drinking; it can provide relief from the heat in other ways.[19] There are four major areas on your body where large blood vessels lie close to the skin surface: the neck, each of the armpits, and the groin area. Putting a cold, wet cloth or an ice pack in those areas will quickly cool you down; it’s what emergency room doctors do to help victims of heatstroke.[20] Even room-temperature water on the back of your neck is better than nothing.
A 2015 study[21] found that applying cold packs to the cheeks, palms, and soles of the feet — which have blood vessels that don’t contract when cold packs are applied — is also effective. Another good way to cool down is to put your hands, which have a high surface area-to-volume ratio, predisposing them to heat loss, and feet in cold water.[22] It can also reduce swelling. Finally, a lukewarm bath,[23] with water at 90ºF (27ºC), has been shown to be one of the most effective methods of cooling.
Whatever you do, don’t jump into a cold body of water like a deep lake, no matter how inviting it may look, because sudden immersion in cold water — which can be as warm as 77ºF/25ºC[24] — can cause a “cold shock” response, which includes an involuntary gasp reflex followed by uncontrollable hyperventilation, both of which will cause you to take water into your lungs and drown.
5. Dress for the heat
In hot weather, choose clothes that are light-colored — because they absorb less of the sun’s radiation than darker clothing — and lightweight. Materials that “breathe” and allow air to flow through the fabric keep you cool by allowing air to circulate without getting trapped, letting it flow past your skin and carry the warmth away from your body while cooler air flows in behind it. Fabrics[25] like cotton and linen are among the most breathable, and high-tech sportswear made from “moisture wicking” fabrics will transport sweat away from your skin to the outer layers of the material, where it can evaporate.
6. Wear sunscreen
Sunburn limits the body’s ability to get rid of heat by compromising skin circulation and sweating. Ultraviolet radiation absorbed by the skin can also damage genetic material and increase the risk of cancer. Experts[26] recommend using a broad-spectrum sunscreen lotion that has a sun protection factor (SPF) of at least 15. You should smear it on about 20 minutes before you go out in the sun. This is because sunscreens are usually emulsion formulas[27] that need to dry and physically bind to skin to form a film. Early application prevents you from immediately brushing or sweating the sunscreen off.
According to a 2012 review,[28] sunscreen is especially important between 10 a.m. and 2 p.m. That said, if you can, it’s best to avoid going outside when the sun is at its strongest, usually between 10 a.m. and 4 p.m. in the Northern Hemisphere. When you do go out, consider wearing a hat, sunglasses, and protective clothing.
7. Activate your pressure points
Acupressure is a traditional Chinese medicine therapy that involves improving energy flow — qi or chi — by applying pressure to key points on the body. It’s like acupuncture, except that it uses manual pressure — from a thumb, finger, or knuckle — instead of needles. Pressure is applied gently and firmly for up to three minutes per pressure point. Pressure points located[29] on your hand (Li 4, Ht 8) and near your elbow (PC 3, Li 11) may assist in cooling you down.
8. Roll your tongue and breathe
Yoga experts swear by a technique called shitali pranayama, which is supposed to have a cooling effect on your body and your mind.
To do the cooling breath (shitali):[30]
- Sit in a comfortable seated position. Close your eyes and relax your body.
- Stick out your tongue and roll the sides in a U shape. (If you can’t do this, purse your lips and make a small ‘o’ shape with the mouth.)
- Slowly inhale through your tongue in this tube position.
- Then close your mouth and exhale out through your nose.
- Repeat it 5-8 times, which should just take about 5 minutes.
You should experience a feeling of coldness on your tongue and the roof of your mouth. With practice, you should be able to increase the duration of the inhalation and increase the cooling effect
9. Keep vigorous exercise to a minimum
Exercising in extreme heat puts extra stress on your body.[31] In order to cool itself down, your body sends more blood to the surface to circulate through your skin. This leaves your muscles with less blood, which, in turn, causes your heart rate to increase. High humidity aggravates the situation by not allowing the sweat to evaporate readily from your skin, which pushes your body temperature even higher. This can lead to cramps, fainting, or, in the worse cases, heat exhaustion then heatstroke. Better to just give yourself the day off.
10. Seek out green spaces
Trees and plants absorb water through their roots and transpire it out of their leaves. This makes their immediate surroundings cooler as the heat from the surrounding air is used to help the water evaporate. Trees also provide cooling shade. During the summer, only 10% to 30% of the sun’s energy reaches the ground below the tree. The rest is either absorbed and used for photosynthesis by the leaves in the canopy, or reflected back into the atmosphere. Research[32] has found that suburban areas with mature trees can be 4 to 6ºF (2 to 3ºC) cooler than suburbs without trees.
References:
- completeptlincoln.com/cpt-benefits-of-staying-hydrated/
- doi.org/10.2114/jpa.21.93
- fruitsandveggies.org/recipes/flavored-ice-cubes/
- theharvestkitchen.com/immune-boosting-flavored-ice-cubes/
- womensrunning.com/health/food/electrolyte-rich-fruits-summer-hydration/
- healthyliving.azcentral.com/evaporating-sweat-cool-down-9657.html
- doi.org/10.1111/j.1748-1716.2012.02452.x
- doi.org/10.1177/0748730414523078
- drinkhydrant.com/blogs/news/does-alcohol-dehydrate-you
- ncbi.nlm.nih.gov/books/NBK236229/#_ddd00166_
- healthline.com/nutrition/19-hydrating-foods
- asweetpeachef.com/easy-fruit-sorbet-recipes/
- www.sbs.com.au/topics/science/humans/article/2016/11/18/how-hot-food-can-cool-you-down-summer
- doi.org/10.1016/j.physbeh.2010.11.018
- epa.gov/sites/default/files/2016-03/documents/eheguide_final.pdf
- who.int/news-room/fact-sheets/detail/climate-change-heat-and-health
- doi.org/10.7326/M19-0512
- apartmenttherapy.com/beating-the-heat-with-low-tech-122423
- www.eurekalert.org/multimedia/796995
- newsnetwork.mayoclinic.org/discussion/keeping-cool-in-blistering-hot-weather/
- doi.org/10.1016/j.wem.2014.11.006
- doi.org/10.1016/S1440-2440(01)80026-8
- ncbi.nlm.nih.gov/books/NBK459311/
- en.wikipedia.org/wiki/Cold_shock_response#Water_temperature
- stitchfix.com/women/blog/fashion-tips/guide-breathable-summer-fabrics/
- fda.gov/consumers/consumer-updates/tips-stay-safe-sun-sunscreen-sunglasses
- labmuffin.com/need-apply-sunscreen-sun-exposure/
- ncbi.nlm.nih.gov/pmc/articles/PMC3460660/
- tcmtips.com/how-to-reduce-body-heat-by-acupressure/
- yogalily.com/shitali-pranayama-cooling-breath/
- mayoclinic.org/healthy-lifestyle/fitness/in-depth/exercise/art-20048167
- doi.org/10.2172/10180633