Today and Monday are expected to be hot and humid. Daytime high temperatures are expected to be in the low thirties with maximum humidex values near forty. Overnight, temperatures are only expected to fall to about twenty or so. While extreme heat can put everyone at risk from heat illnesses, health risks are greatest for – older adults – infants and young children – people with chronic illnesses such as breathing difficulties, heart conditions or psychiatric illnesses – people who work in the heat – people who exercise in the heat – people without access to air conditioning and – homeless people. Drink plenty of liquids especially water before you feel thirsty to decrease your risk of dehydration. Thirst is not a good indicator of dehydration. Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion. Environment Canada meteorologists will update alerts as required. Please monitor local media or Weatheradio. To report severe weather, send an email to firstname.lastname@example.org or tweet reports to #ONStorm.