Health Canada recommends an upper indoor temperature limit of 26°C to protect older adults from heat-related illness and death. This threshold is based on a rapid evidence review of available epidemiological studies and controlled exposure research, and aligns with World Health Organization guidance and policies in several Canadian jurisdictions.
Research indicates that indoor temperatures above 26°C increase physiological strain and risk of heat-related illnesses; sustained exposure to indoor temperatures between 26°C and 31°C, especially overnight, should be avoided whenever possible. While focused on older adults, these measures may also support broader population health during heat events.
As a non‑prescriptive resource, the guidance document is intended to support evidence‑based action for public health officials and other decision makers developing policies or strategies to reduce heat‑related health risks for older adults. It does not impose any requirements.
