Building Heat Resiliency in the Face of a Warming Climate

2023 was the world’s hottest year on record, according to the National Oceanic and Atmospheric Administration (NOAA), which released the analysis early this year. “Not only was 2023 the warmest year in NOAA’s 174-year climate record,” NOAA Chief Scientist Dr. Sarah Kapnick said, “it was the warmest by far.”1 Last summer, nearly every continent on the planet saw record-breaking temperatures, with June through August being the hottest three-month period in recorded history. This kind of heat is not just uncomfortable—it can be deadly. 


Illustration of a person running outdoors in the sun and another on their knees sweating


Data from the United States show that an increase in days 90 degrees and above is associated with an average of 1,373 extra deaths each year.2 Meanwhile, research published in 2023 estimated that more than 61,000 people died from heat-related causes in Europe between May 30th and September 4th 2022, Europe’s hottest summer on record. Elderly people—especially women—were the most affected.3 Infants and young children, pregnant women, those with chronic medical conditions, athletes, outdoor and agricultural workers, and lower-income populations are also more vulnerable to extreme heat.4 But our bodies have an incredible ability to adapt to our environments, and this is true with building adaptability and resiliency to heat.  

What extreme heat does to the body (why is it so dangerous?)

Illustration of a person walking while looking sweaty and exhausted

We’ve all been overheated at one time or another, but there is a point when the exposure to extreme heat becomes dangerous. Sweating profusely for an extended period can lead to dehydration (and electrolyte loss), which can make it harder for the body to maintain normal blood pressure, putting strain on your heart and kidneys. Extreme heat can create more heat inside the body, making it hard for the heart, lungs, and brain to function properly. The most extreme version of this is heat stroke, in which the body’s temperature rises too rapidly and the body is unable to cool down; left untreated, heat stroke can damage organs, and in worst cases, cause them to shut down, leading to death.5 But most heat-related deaths aren’t caused by heat stroke, but rather, heart attacks or some other cardiovascular event. When our bodies heat up, the heart is the main organ working to cool us down by pumping more blood to the surface of the skin to release excess heat. This extra strain on the heart—especially in those with poor cardiovascular health or older individuals—can be deadly.6

Build Your Resilience to Heat

Illustration of a person choosing a salad over a hamburger

Of course, there are common sense measures to take to reduce the risk of harm from extreme heat: stay hydrated!; if you can’t be inside in air conditioning, find shade; wear loose-fitting, breathable clothing; don’t exercise or exert yourself in extreme heat conditions (this is especially true for those with existing conditions and older people); and give your body time to acclimate—spend a short time outside in the hottest part of the day for several days to let your body become accustomed to the heat. Beyond these basics, there are other ways we can help our bodies build resilience to heat. 

Cool, refresh, and replenish with diet

Think of the foods you’d want to eat on the hottest summer day. They are likely light and refreshing, the opposite of the rich comfort foods we crave in the fall and winter months—that’s your body’s wisdom speaking. Listen. Eat the cooling foods! Think salads, fresh veggies and fruit, and light proteins with cooling herbs like mint and parsley. Avoid inflammatory foods like fried food, refined carbohydrates, omega-6 vegetable oils, heavily processed foods, sugar, and alcohol. Research also points to the importance of supporting a healthy insulin response to help the body better cope with high temperatures and reduce heat-induced damage.7 Eliminating, or strictly limiting, those inflammatory foods mentioned will go a long way to support healthy blood sugar and insulin response. Finally, ensuring you include lots of polyphenol-rich foods in your diet can support the health and normal functioning of your hypothalamus, an area of the brain responsible for maintaining body temperature, among other things.8 Polyphenols are a family of antioxidants found in berries, wine, green and black tea, and other plant foods. Supplements like quercetin and resveratrol are polyphenols too.

Illustration of a glass of water with a check mark and a cup of coffee with an x-mark

Staying hydrated (all day long, not just when you feel thirsty) may be the single most important thing you can do to support your body during times of extreme heat, but sorry to say, your iced latte doesn’t cut it. Just as important as staying hydrated is what you hydrate with. Water is the gold standard, but if you are sweating a lot (e.g., working or exercising outdoors or in extreme heat conditions) replacing lost electrolytes becomes a must because they are lost through sweat. Electrolytes—sodium, potassium, calcium, magnesium, and chloride—are essential for basic life functioning and a loss or imbalance can disrupt normal body functions, possibly leading to life-threatening complications. You can buy electrolyte powders or liquids to add to your water, or you can simply add a little sea salt: a common amount recommended for “endurance activities” is ¼ to ½ teaspoon of sea salt per liter of water.9 Coconut water has a natural cooling effect that helps reduce heat stress and is a good source of electrolytes, particularly potassium.10

Support, strengthen, and protect with supplements

Optimizing nutrient intake of foundational supplements like vitamin C, the B complex, and magnesium helps our bodies be more resilient to the extra stress hot weather puts on them, as well as ensuring we replenish what is lost through sweat. Research on vitamin C and heat adaptation goes back decades and shows that vitamin C “…may reduce the physiological responses to heat stress” and improve acclimatization to high temperatures. Effective doses were between 250 and 500 mg/day.11 The B vitamins are intricately involved in cellular energy production; optimizing your B vitamin intake could combat the feelings of lethargy and low energy induced by high temperatures. One study found that high school athletes who took a B-complex supplement during exercise in hot weather experienced less fatigue compared to those who did not take the supplement.12 Magnesium plays a role in thermoregulation, or the body’s ability to regulate its temperature, and a majority of people just don’t get enough of this important mineral.13 It is also one of the electrolytes lost during profuse sweating. Finally, magnesium is needed for vasodilation, or the relaxation of blood vessels, important for maintaining good cardiovascular health, which becomes critical during extreme heat.

Building heat resiliency has become something that modern humans have to do in a warming world. Focusing on supporting your overall health, especially cardiovascular health, is one of the key ways in which to do that. Feel like you need a little guidance in your health journey? Natural Grocers’ Nutritional Health Coaches (NHCs) are always there for one-on-one consultations to help you empower your health! 

Want to Beat the Heat? Get Moving!

Illustration of person running outdoors

Exercising may be the last thing you want to do when it’s very hot outside—and of course you shouldn’t push yourself in extreme temperatures—however, a lifetime of regular physical activity can go a long way in helping our bodies adapt to heat and support good cardiovascular health. Research published in late 2023 says that “By frequently increasing core temperature and sweating, as well as stimulating the cardiovascular system, regular physical activity … in temperate conditions leads to several physiological adaptations that increase heat tolerance and help in meeting the increased demands placed on the cardiovascular system during heat stress.” It goes on to say that regular physical activity in a hot environment provides “even greater and additional” heat adaptations, including “a lowered resting core temperature, improved vasodilation in the skin (this helps release heat), increased sweating capacity, improved cardiac function, expanded blood volume, and enhanced cellular protection.” The researchers point out that this is especially important for today’s youth, who will be more exposed to extreme heat in the future. “By maintaining regular physical activity and adequate physical fitness throughout their lives, they may be better equipped to meet these challenges.”14


  1. National Oceanic and Atmospheric Administration. “2023 was the world’s warmest year on record, by far.” January 12, 2024.,was%20the%20warmest%20by%20far.
  2. National Heart, Lung, and Blood Institute. “Extreme heat in the U.S. linked to an increased number of deaths.” June 21, 2022.
  3. Ballester, J., Quijal-Zamorano, M., Méndez Turrubiates, R.F. et al. Heat-related mortality in Europe during the summer of 2022. Nat Med 29, 1857–1866 (2023).
  4. Centers for Disease Control and Prevention. “Protecting Disproportionately Affected Populations from Extreme Heat.” August 25, 2022.
  5. Mayo Clinic. “Heat Stroke.”
  6. Kenney WL, Craighead DH, Alexander LM. Heat waves, aging, and human cardiovascular health. Med Sci Sports Exerc. 2014 Oct;46(10):1891-9. doi: 10.1249/MSS.0000000000000325. 
  7. Rhoads RP, Baumgard LH, Suagee JK, Sanders SR. Nutritional interventions to alleviate the negative consequences of heat stress. Adv Nutr. 2013 May 1;4(3):267-76. doi: 10.3945/an.112.003376. 
  8. Samodien E, Johnson R, Pheiffer C, Mabasa L, Erasmus M, Louw J, Chellan N. Diet-induced hypothalamic dysfunction and metabolic disease, and the therapeutic potential of polyphenols. Mol Metab. 2019 Sep;27:1-10. doi: 10.1016/j.molmet.2019.06.022.
  9. Hui A. “Does Adding Salt to Drinking Water Boost Hydration?” Health, June 22, 2023.
  10. Vavrek K, MS, RD, CSSD. Is coconut water healthy? The Ohio State University Wexner Medical Center. Aug 27, 2019.
  11. Strydom NB, Kotze HF, van der Walt WH, Rogers GG. Effect of ascorbic acid on rate of heat acclimatization. J Appl Physiol. 1976 Aug;41(2):202-5. doi: 10.1152/jappl.1976.41.2.202. 
  12. Early, R.G., Carlson, B.R. (1969). Water-soluble vitamin therapy in the delay of fatigue from physical activity in hot climatic conditions. Int Z Angew Physiol Einschl Arbeitsphysiol. 27, 43-50.
  13. DiNicolantonio JJ, O'Keefe JH, Wilson W. Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis. Open Heart. 2018 Jan 13;5(1):e000668. doi: 10.1136/openhrt-2017-000668. 
  14. Deshayes TA, Périard JD. Regular physical activity across the lifespan to build resilience against rising global temperatures. EBioMedicine. 2023 Oct;96:104793. doi: 10.1016/j.ebiom.2023.104793