3. It is a prolonged period of excessive heat, often accompanied by
excessive humidity.
Heat waves occurs when there are a number of consecutive days
with above average temperature, that the body can not tolerate.
The unusual and uncomfortable hot weather can impact on human
and animal health and cause disruption to community infrastructure
such as power supply, public transport and services.
Heat wave
5. Heat waves kill and injure
Heat wave is one of the major
disaster for many countries,
develops slowly and kills and
injures many animals and
people more than any other
disaster.
Hence called as silent disaster
In India the condition becomes
more severe in May and June
6. As the temperature rises , people , animals and
plants suffer from heat stress
Apart from death , every day more and more
people are admitted with suffering sunstroke
and severe dehydration, vomiting and high fever.
7. Heat wave caused unfold mystery to people all over the
world. In 1998, about 1500 people were died in China and
in 1997 about 2000 people fell into heat wave in Greece
Similarly in India the heat wave took 302 lives in the year
1998 and more than 2000 people in the year 2002. In
Orissa, heat wave caused 2042 deaths in 1998 and more
than 1200 deaths in 2002 in southern India
Data collected by IMD reveals that the average annual loss
of human life due to heat wave over India is 153
9. Effect on human beings
In many parts of world , every summer, thousands of people
suffer from heat stress where their bodies absorb more heat
than they expel.
Depletion of salt and electrolyte in the body may cause heat
cramp.
Hard work under direct sun may lead to heat exhaustion.
Usually, it is the cumulative effect of hot days without the
relief of cool nights and exposure to exhaustion.
Sunburn can retard the body’s ability to shed heat, and may
increases the severity of the heat disorder
10. In severe heat there is dehydration and body may
overheat, leading to a heat related
illness.[HYPERTHERMIA]
A heat related illness may result in irreversible damage to
body, including the brain or even death.
Asphalt and concrete store heat longer and gradually
releases heat at night, which produces significantly higher
night temperatures in urban areas known as the urban
heat island effect.
14. Like human beings, animals
too suffer, particularly when
they are left in direct sun
and they do not get adequate
water.
Domestic animals and
poultry birds are particularly
vulnerable to heat wave.
When there is not enough
shade or water for animals,
they may change their
behavior.
Animals will look for
shelter from the heat under
trees or near bushes, start
sweating and panting,
drooping, drink more water
and have reduced appetite
for food.
15. Agriculture and crop
Heat waves also damage plants, crops
and vegetables. When shearing winds
blow and the temperature rises to
around 45 ⁰ C, exotic plants perish.
When temperature exceeds 45 ⁰ C for
a number of days even the traditional
species suffer, particularly if they do
not receive moisture regularly.
In the grazing field not a single blade
of grass is available for the cattle.
16. During heat wave, the railway lines can expand to the point
where they buckle and cause derailment of train.
Road damages can also occur with bitumen melting and
having cracks.
Long periods of extended heat can soften and crack the
asphalt in roads and streets. Concrete and highways have
been known to shatter explosively from periods of excess
heat. Even bridges may have similar type of damages.
Infrastructure
17. During hot summer water consumption
increases drastically and often causing
shortage of drinking water.
Lack of water in most of the wells, pond, tube
well and other bodies during hot summer
seasons, which has an adverse effect on
human being and animal population.
18. During a heat wave algae growth rates
increase, which lowers the oxygen content of
the water. The reduced oxygen level
combined with heat stress can lead to large
scale mortality in wild fish.
Drought conditions from a heat wave
increases the occurrence of wildfires. Wildfire
kills many animals and destroys the
vegetation.
Continued heat wave conditions can also
cause crop failure due to lack of rain.
19. Prevention during heat wave
Heat waves can be serious but it is one of
the disasters, which can be managed
easily.
1. Control the temperature at home
2. In the street, avoid direct sunlight
3. Take care of pets and other animals
by avoiding direct exposure to sun
4. Keep rooms cool by using shade
cloth or reflective material on the
outside of the window
5. Limit physical activity at the hottest
times of the day
20. Drink a lot of water about 2 to 3 litres daily.
Listen to local weather forecast so that we can know if a heat wave is on the way
Avoid heavy protein foods like meat, dairy products etc., which raise body heat
and increase fluid loss
If you must go out then wear light weight, light coloured, loose, porous clothes, a
wide brimmed hat and sunscreen and regularly rest in shade and drink fluids
Do not leave children or pets in parked vehicles. Temperature inside a closed
vehicle can reach over 140⁰F within minutes. Exposure to such high temperatures
can kill in minutes
22. The state and district control rooms should make
necessary arrangement for flashing the warning
through all forms of media
Simultaneously, departments like health and
other related departments need to remain alert
and put necessary emergency measures in place
Interview local officials and representatives of the
Department of Agriculture about special steps
farmers can take to establish alternative water
supplies for their crops and ways to protect
livestock and poultry from the extreme heat
