An official from the Glasgow Electric Plant Board says the entire city of Glasgow's power was shut off for a short while Tuesday afternoon.
A substation shut down after officials detected a failure, a short while later another substation became out of service.
About 4,000 homes were without power for 45 minutes.
Power has since been restored.
Officials expect to run into similar problems Wednesday because of the heat.
They advise residents to use as little power as possible between the hours of 12 p.m. to 8 p.m.