New Study Reveals Lower Threshold for Heat Stress Impacting Human Body Regulation

A recent study highlights that the human body struggles to regulate temperature under heat stress conditions previously considered moderate, raising concerns amid rising summer temperatures in Israel. Conducted under controlled environmental conditions, the research found that when combined temperature and humidity reach between 26 and 31 degrees Celsius, the body begins to fail in maintaining thermal balance. Above this threshold, body temperature continues to rise, risking heat stroke within hours.

Professor Maya Negev from the University of Haifa, a member of the Climate Scientists Forum, explained that the body cools itself mainly through blood flow to the skin and sweating, but these mechanisms are limited, especially when humidity is high and sweat evaporation is less effective. The study emphasizes that not only temperature but also humidity significantly affect heat stress.

The research also points to increased health risks during heat waves, including higher mortality rates among the elderly, and elevated risks of heart attacks and strokes. Vulnerable groups include people with chronic illnesses, pregnant women, infants, children, and socioeconomically disadvantaged populations, who have fewer means to protect themselves. Negev stressed that climate change exacerbates these health, economic, and social disparities.

Israel and the broader Middle East are identified as climate change hotspots, facing intensified heat and humidity. Negev advocates for urban planning improvements, such as better building designs and reduced reliance on air conditioning, which can contribute to environmental warming if overused. She also highlights the importance of shading in public spaces, reducing vehicle use, and enhancing public transportation and cycling infrastructure to mitigate urban heat.

The Israeli healthcare system faces challenges in preparing for climate change impacts amid other emergencies, but Negev calls for integrated efforts to create healthier environments as temperatures rise. This study underscores the urgent need for adaptation strategies to protect public health in increasingly hot and humid conditions.