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 heat and humidity reach a range of 26 to 31 degrees Celsius on a specific index, the body’s ability to maintain stable internal temperature diminishes significantly. Above this threshold, body temperature continues to rise, increasing the risk of heat stroke within hours.

Professor Maya Negev from the University of Haifa explains that the body cools itself primarily through blood flow to the skin and sweating, but these mechanisms become less effective as humidity rises, reducing sweat evaporation. The study underscores that heat stress is not solely about temperature but also humidity, which together exacerbate physiological strain.

The health risks extend beyond heat stroke, including increased mortality, heart attacks, and strokes, especially among vulnerable groups such as the elderly, people with chronic illnesses, pregnant women, infants, and socioeconomically disadvantaged populations. Negev emphasizes that climate change intensifies these risks, particularly in Israel, identified as a climate change hotspot, necessitating urgent adaptation strategies.

To mitigate heat stress, urban planning improvements like better building designs, reduced reliance on air conditioning, increased shading, and enhanced public transportation are recommended. These measures aim to reduce urban heat islands caused by vehicles, asphalt, and lack of shade, where surface temperatures can reach 70 degrees Celsius by mid-morning. The Israeli healthcare system faces challenges preparing for these climate impacts, which affect multiple sectors, highlighting the need for integrated environmental and public health strategies.