The Science of Summer Wellness: How heat affects hydration, energy and appetite - and how to support your body intelligently
Summer can make us feel lighter, more active and naturally drawn to fresher foods. But warmer weather also changes how the body regulates temperature, fluid balance and energy.
Understanding these changes can help you support your body more intelligently throughout the season.
Heat and hydration
When the temperature rises, the body increases blood flow to the skin and produces sweat to help release heat. This cooling process also increases the loss of water and electrolytes.
Research shows that dehydration can increase physical strain and may affect mood, concentration and feelings of fatigue.[1][2]
The most effective approach is to drink regularly throughout the day rather than waiting until you feel very thirsty. Water should remain the foundation of hydration, supported by water-rich foods such as fruit, vegetables, yoghurt and soups.
Electrolyte drinks are not always necessary. For most normal summer days, water and balanced meals are sufficient. They become more relevant during prolonged exercise, heavy sweating or extended periods outdoors in high temperatures.[3]
Why heat affects energy
In warm conditions, the heart works harder to move blood towards the skin while continuing to supply the muscles and other organs.
This means that exercise, walking and even everyday tasks can feel more demanding than they would in cooler weather. Studies have shown that higher temperatures can increase physiological strain and reduce endurance performance.[4]
Rather than pushing through, adjust your routine to the conditions. Exercise earlier in the morning or later in the evening, choose shaded routes and allow more time for rest and recovery.
Feeling tired in summer does not always mean you need more caffeine or sugar. It may simply be a sign that you need more fluid, food, sleep or time away from direct heat.
Why appetite may change
Many people find that their appetite decreases during warmer weather. Research suggests that exposure to heat may reduce food intake in some people, although the effect varies between individuals.[5]
Lighter meals can feel more appealing, but it is still important to ensure they are nutritionally balanced.
Try to include:
- protein from eggs, fish, tofu, beans, lentils or yoghurt;
- colourful fruit and vegetables;
- fibre-rich carbohydrates such as oats, quinoa, potatoes or whole grains;
- healthy fats from seeds, nuts, avocado or olive oil.
Cold grain bowls, smoothies, salads and overnight oats can all work well, provided they contain enough protein, fibre and energy.
Supporting your summer routine
Summer wellness does not need to be complicated. A few consistent habits can make a meaningful difference:
- Drink water regularly throughout the day.
- Move strenuous exercise away from the hottest hours.
- Choose lighter meals that still provide balanced nutrition.
- Prioritise rest and recovery, particularly after time in the heat.
- Keep nourishing options readily available.
Our frozen superfood juices fit naturally into this kind of summer routine. Each 30ml sachet is designed to offer a simple, convenient way to include concentrated plant ingredients in your day.
They are not a water replacement, but they can form part of an easy summer wellness ritual.
Try our Organic Wheatgrass Juice alongside breakfast, Beetroot & Maqui Juice as part of a colourful morning routine, or Apple, Ginger & Turmeric Juice for a fresh and vibrant afternoon refresher.
Work with the season
Supporting your body in summer is not about following a perfect routine. It is about responding to changing needs.
More water, lighter, balanced meals, gentler movement and simple nutrition habits can help you feel refreshed and well supported throughout the warmer months.
Scientific references
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Périard JD, Eijsvogels TMH, Daanen HAM. Exercise under heat stress: thermoregulation, hydration, performance implications, and mitigation strategies. Physiological Reviews. 2021. View the study.
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Zhang J et al. Effects of water restriction and supplementation on cognitive performance and mood among young adults. International Journal of Environmental Research and Public Health. 2021. View the study.
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Anastasiou CA et al. Sodium replacement and plasma sodium during exercise in the heat. Journal of Athletic Training. 2009. View the study.
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Jenkins EJ et al. Delineating the impacts of air temperature and humidity for endurance exercise. Experimental Physiology. 2023. View the study.
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Zakrzewski-Fruer JK et al. Acute exposure to a hot ambient temperature reduces energy intake in men during rest. British Journal of Nutrition. 2021. View the study.