Plan outdoor exercise around more than temperature

Start with the hour, not only the day

Conditions can change substantially between morning, midday and evening. Check an hourly view and look for a cooler, cleaner window that fits the intended intensity of your workout.

A simple pre-workout check

1. Review heat, humidity and the local heat alert.
2. Review AQI and the pollutant driving it.
3. Reduce duration or intensity when conditions are less favorable.
4. Choose an earlier or later hour when possible.
5. Stop activity and move to a cool place if you feel faint or weak.

How HiAir approaches the decision

HiAir combines available environmental signals with your activity context and sensitivity settings, then explains why a time window looks better or worse. Missing forecast data stays missing; it is not silently invented.

Primary references: CDC — Heat and Athletes and WHO — Heat and health.