In heatwaves and los niños, not only humans need help, plants and all animals need help too.

When the outside temperature significantly exceeds your body temperature, you absorb heat from the environment instead of releasing it. The body shifts into high-gear to cool itself, a taxing process that strains the heart, severely dehydrates you, and—if left unmanaged—can lead to hyperthermia and organ failure. [see https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health]

The cooling Response: - Vasodilation: Blood vessels near the skin dilate (open up) to divert warm blood away from your internal organs and toward the skin’s surface, where the heat can be radiated away. - Increased Heart Rate: Pumping extra blood to the skin forces your heart to work significantly harder, placing heavy stress on your cardiovascular system. - Sweating: The body produces sweat. As it evaporates from the skin, it cools the body. Note: In highly humid conditions, sweat cannot evaporate, severely hampering this crucial cooling mechanism.

Heat Stress and Heat exhaustion: If the outside environment overpowers these cooling mechanisms, your core temperature begins to rise. You may experience: Heavy sweating followed by fatigue and weakness. Dizziness, lightheadedness, and fainting (caused by the drop in blood pressure). Nausea, headaches, and muscle cramps.

Critical Emergency - Heatstroke (Hyperthermia): Once your core temperature rises from the normal ~ 37°C to above 40°C, the body’s internal systems start to break down. - Neurological Impact: Reduced blood flow and oxygen to the brain can cause confusion, memory loss, and seizures. - Organ Failure: Extreme heat causes proteins in the body to denature (change shape and stop working). The heart muscle may suffer arrhythmias, and organs like the kidneys and gut begin to suffer acute injury from intense dehydration and lack of oxygen. - Death: If core temperature continues to rise to around 41°C-42°C, multiple organ failure occurs, which is fatal without immediate medical intervention.

How to stay safe as temperatures rise [from NIB Australia] Hot weather isn’t just uncomfortable - it can put real strain on your body. Here are some simple ways to stay cool and protect yourself: - Stay hydrated - Drink water regularly, even if you’re not thirsty. Avoid caffeine or alcohol, which can dehydrate you. - Keep cool - Use fans, air conditioning or cool showers. Stay indoors during the hottest part of the day (usually 11am–3pm). - Wear light clothing - Choose loose-fitting, light-colored clothes made of natural fibres like cotton or linen. [None of those westernized business suits.] - Take it easy - Avoid heavy exercise or outdoor activity when it’s hottest. Rest in the shade or indoors. - Check on others - Young kids, older adults and people with medical conditions are more at risk in extreme heat. [Look out and care for them.]

NB.
To explore how heat indices and humidity thresholds dictate your environment’s danger, check out the World Health Organization Heat and Health Guide or learn about critical environmental limits on The Conversation. Heat and health - World Health Organization (WHO)28 Apr 2026 — How does heat impact health? The amount of heat stored in the human body is determined by a combination of (a) an inability to eli… World Health Organization (WHO) –What’s the Highest Temperature the Human Body Can Handle?4 Dec 2025 — So, how hot is too hot? https://theconversation.com/how-hot-is-too-hot-for-the-human-body-our-lab-found-heat-humidity-gets-dangerous-faster-than-many-people-realize-185593
The Conversation put together an infographic that shows what heat and humidity your body could survive in. [NIB] Extreme Temperature Safety: Heat- and Cold-Related Illness25 Sept 2024 — sweating heavily. exhaustion or fatigue. dizziness or lightheadedness. blacking out or feeling dizzy when standing up. weak but … https://www.nib.com.au/the-checkup/everyday-health/general-health-guides-and-faqs/whats-the-hottest-temperature-the-human-body-can-cope-with

NB. For animals the ranges depend on whether they are endothermic (warm-blooded) or ectothermic (cold-blooded). Mammals range is 36°C - 40°C; birds 40°C - 43°C; reptiles and other cold blooded animals have ranges depending on their environment (- more adaptable the us).
Insects have a range of temperatures (from minimum 10°C - 15°C to maximum 40°C - 45°C) where they can survive. Outside that range their survival chance drops rapidly.

For pollinators like bees, high temparature reduces their available time to seek nectar and pollens (flower blooms also wilt quickly); body size (so they cannot carry as much food back to base); and fertility (thus, reduces their population).

For fish, warm water holds less oxygen (leads to suffocation), speeds up fish metabolism (so need to eat more and use more oxygen), and makes the water more suitable for [toxic] algae to glow (use more oxygen and make barrier for oxygen in air to dissolve in water). Fish already have it tough with untreated wastes in water. [Residues of detergents and shampoos and soaps reduce oxygen exchange between air and water. Please consider impacts on fish and minimize your use of detergents.]

The effects on plants and flowers (and food for insects): degraded nutritional value (as photosynthesis works best within a range of temperature too); less number and/or small sized flowers; pollen quality (at typically 30°C - 32°C the proteins needed for metabolism of pollen break down), this can reduce the size of ‘pollen tubes’ and disrupt fertilization, thus -no fruits or fruits with fewer seeds.

Some plants and insects have their behavior (activity) tied to (or evolved) with temperature ranges. Outside these ranges, their schedule/clock goes wrong.

some 90 - 95 % of global heat is absorbed in the global water cycle (which generates water vapor which rises up (with heat) and gathers to become clouds, which condense and rain). The more heat, the more water vaporizes, the more and heavier rains and floods. Unfortunately, where and when and how much rains would fall at a place on land is still extremely hard to predict in advance. Luckily, most (80+% of) water cycle events happen over oceans.

How can we help?
In heatwaves and los niños, not only humans need help, plants and all animals need help too. - More water will have to be made available and water storage be managed - Cooling devices (shades, shelters, mulches, fans,… ) and/or air circulation (air conditioning cools a small spaces while heats the outside environment) - In the medium to long term: reducing use of energy sources that produce CO₂, designing and landscaping for natural air circulation, minimizing CO₂ and energy use, implementing water and energy distributions, and ecological sustainable environment,…

Perhaps, we can focus on self-perpetuating [socio-cultural and technological] infrastructures that would continually drive changes toward more temperate and stable environment and save the world.