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Weather Alerts and Warnings
Heat Warnings
Extreme heat events can put the public at risk of heat-related illnesses. Four environmental factors work together to make it hot enough to put health at risk. This includes high temperature, high relative humidity (moisture in the air), radiant heat (from the sun) and low wind speed (lack of air movement). Additionally, an individual’s health can depend on their sensitivity, acclimatization and their own as well as their community’s adaptability to extreme heat.
The Haldimand-Norfolk Health Unit’s Medical Officer of Health issues a Heat Warning or an Extended Heat Warning upon notification from Environment Canada and Climate Change Canada that certain extreme heat thresholds have been met. Details for each warning and their triggers can be found below.
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A Heat Warning will be issued when:
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![]() Extended Heat Warning |
An Extended Heat Warning will be issued when:
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Heat Affects Everybody.
Heat illnesses are preventable and knowing the risks and how to protect yourself and your family will keep you safe over the summer. Much like a fever, extreme heat stresses your body’s ability to maintain its normal temperature and can lead to a heat stroke. When out in the heat, watch for symptoms of heat illness, which include:
- dizziness or fainting;
- nausea or vomiting;
- headache;
- rapid breathing and heartbeat;
- extreme thirst; and
- decreased urination with unusually dark yellow urine.
If you experience any of these symptoms during extreme heat, immediately move to a cool place and drink liquids. Water is best. A list of heat-related illnesses and their symptoms can be found below from the Government of Canada website:
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Health Effects |
Causes and Signs |
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Heat Stroke | The most serious type of heat illness is a result of body heat overload. Signs of heat stroke may include a core body temperature of more than 40C/104F, complete or partial loss of consciousness and/or reduced mental ability. Sweating is not a good indicator, as there are two types of heat stroke:
Classic – accompanied by little or no sweating, usually occurring in children, those who are chronically ill and older adults. Exertional – accompanied by an increase in body temperature because of strenuous exercise or occupational exposure in combination with environmental heat, and where sweating is usually present. |
Heat Exhaustion | Caused by excessive loss of water and salt. Symptoms may include heavy sweating, weakness, dizziness, nausea, headache, diarrhea and muscle cramps. | |
Heat Fainting | Caused by the loss of body fluids through sweating and by lowered blood pressure due to pooling of blood in the legs. Symptoms include temporary dizziness and fainting resulting from an insufficient flow of blood to the brain while a person is standing. | |
Heat Cramps | Caused by a salt imbalance resulting from a failure to replace salt lost through excessive sweating. Symptoms are sharp muscle pains. | |
Heat Rash | A result of inflammation of clogged sweat glands and accompanied by tiny red spots on the skin, which may give a prickling sensation. | |
Heat Edema | Heat-induced swelling frequently noticeable in the ankles, feet and hands, and most often seen in people who are not regularly exposed to heat |
Who is Most at Risk?
Where Can I Go To Cool Down?
During Heat Warnings or Extreme Heat Warnings participating service providers in Haldimand and Norfolk counties will provide designated sites and recreational activities to help you cool down. A list of locations and services can be found below.
Stay COOL at these Facilities (NOTE: These facilities may be closed or have limited hours/capacity during COVID-19)
Norfolk County Cooling Centres
Norfolk County Public Libraries
Branches in: Delhi, Port Dover, Port Rowan, Simcoe and Waterford
Visit olc.ncpl.ca to view individual branch locations and hours.
Recreational Services in Norfolk County to Help You Beat the Heat Haldimand County Public Libraries Caledonia Branch – Check branch hours and address Cayuga Branch – Check branch hours and address Dunnville Branch – Check branch hours and address Hagersville Branch – Check branch hours and address Jarvis Branch – Check branch hours and address Selkirk Branch – Check branch hours and address Free Recreational Services in Haldimand County to Help You Beat the Heat *Free services for Haldimand County residents only. Proof of residence in Haldimand County required. What Else Can I Do to Prevent Heat Related Illnesses? The HNHU recommends taking the following actions to stay cool and prevent heat-related illness: Other Weather Warnings Other local weather warnings (such as air quality or thunderstorms) can be found on the Environment and Climate Change Canada.