Hyperthermia refers to a group of conditions that can occur when the body system cannot handle extreme heat. This can be due to overexposure to heat or overexertion. Hyperthermia includes heat stroke and heat exhaustion. For more information on heat stroke and heat exhaustion and how these can affect children, see Keep children cool! Protect Your Child from Extreme Heat.
Children are especially vulnerable to overheating and developing a heat-related illness such as heat stroke or heat exhaustion. Extreme heat affects infants and young children quickly because of their physical size. Babies and children sweat less, reducing their bodies’ ability to cool down. Children can go into shock quickly. Heat can also make existing illnesses, like asthma, worse.
Leaving children alone in vehicles during hot weather is particularly dangerous. Vehicles can become very hot in a matter of minutes, even if windows are left open. When the outside temperature is 34 degrees Celsius, the temperature inside a vehicle can reach 52 degrees Celsius in 10-20 minutes.
There is not a lot of data on hyperthermia deaths in Canada. Although considered rare, parents and caregivers should be aware that hyperthermia deaths can happen. Between 2013 and 2018, six children in Canada died from hyperthermia after being a left in a vehicle. This is an average of one child death per year. For more information about heat-related vehicle deaths in Canada, visit Paediatric hyperthermia-related deaths while entrapped and unattended inside vehicles: The Canadian experience and anticipatory guidance for prevention.