But it has been found that the boiling heat of a sultry summer, for example in the initial stages of the onset of the monsoon in India, rather than the scorching heat of a peaking summer, contributes to an increased incidence of heat stress and death, unlike what people generally believe.

Especially it should be ensured that the employers adhere to the basic minimum requirements as regards the environmental conditions of work, providing facilities as demanded by the work stress in tropical climes. Proper ventilation for indoor work, mid-day break, timely right and light food, avoiding tea, coffee, cola drinks and sodium solutions, avoiding hard work during high heat, keeping hydration levels and frequent breaks in work, providing first aid etc need to be looked into.

The laxity on the part of employers due to various reasons is also an alarming signal in developing countries where the economic and attitudinal weaknesses of workers are exploited to their advantage.

The sad deaths of a Delhi TV reporter, Akshay Singh, who travelled through the hot, humid central India probably ill-equipped, on assignment regarding a Madhya Pradesh Professional Examination Board (MPPEB) scam, also known as Vyapam scam, and of a college dean, Arun Sharma, who came to Delhi all the way from Jabalpur are indicators. No foul play was found in the initial investigations. Although it provided ammunition to underdeveloped Indian politicians to seize the opportunity to target their rival parties.

The first symptoms of heat stress are exhaustion, headache, heavy sweating, paleness, muscle cramps, fatigue, vomiting, confusion, fainting, etc. The patient should be taken to a cool area, fanned and wrapped with wet cloth, and water and electrolytes given immediately, and then moved to the clinic. Obesity, high blood pressure, dehydration and alcohol consumption are usually ignored risk factors that in combination may work as immediate causes for triggering the stress.

An International Labour Organisation (ILO) study says heat stress occurs when a person’s environment constituted of air temperature, radiant temperature, humidity and air velocity, clothing and activity and work interact to produce a tendency for body temperature to rise (Note here, that a high physical temperature is not the single contributing factor). The human thermoregulatory system responds by perspiration, which consequently induces a fatal strain on the body, leading to the symptoms.

Several indices have been developed to gauge heat stress proneness like Wet Globe Temperature (WGT) index certified by the ILO and incorporated in its encyclopaedia of occupational health and safety heat stress indices. A series of Kestrel pocket airflow trackers are also in use in various parts of the world. These instruments calibrate heat stress of a time and place through a heat stress index.

According to the ILO calculations, a heat stress index is a single number which integrates the effects of some six basic parameters in any human thermal environment. Others have a two-layer graphic system showing humidity and the physical temperature and then calculating the tolerance level in digits. The likely thermal strain on the body is indicated with a graded warning reaching up to the point when that strain is likely to become unacceptable.

The heat stress index has been defined as the relation of the amount of perspiration required as related to the maximum ability of the average person to perspire.

So scientists are asking us not just to depend on our thermometer but also consider the relative humidity to determine the safety levels of an environment. However, taking precautions will be more useful than having to carry a portable meter to measure stress while you are outdoors.

A simple heat index (HI) combines air temperature and relative humidity and determines the human-perceived equivalent temperature or how hot it feels to the person. It is also called the 'felt air temperature.' For example, even without taking into account the risk factors, if the temperature is a tolerable 40 deg C with a humidity of, assuming, 65%, the heat index or the cumulative heat can be about 61 deg C at which you won't exist.