Firefighters were called to a home off the Crescent, near Marlow Road, in Maidenhead at about 2pm after the carbon monoxide alarm had started sounding and the pair had begun to feel unwell.
A crew from Maidenhead evacuated the property and gave them oxygen, before paramedics arrived with a breath analyser and took them to hospital.
They have apparently both now returned home.
A carbon monoxide monitor was also sent out from Reading, which recorded carbon monoxide levels of between 40 and 80 parts per million in the house. Any level above zero is considered unsafe.
The National Grid was contacted to isolate the gas supply from the house, which was then ventilated.
The gas leak is believed to have come from the boiler.
Speaking afterward, watch manager Chris Havers said: “The moral here is to get a carbon monoxide alarm and if it goes off don’t assume it’s a safety or just ignore it – get out of the house and call the fire brigade.
“Also, if you’ve got anything that burns carbon, get a battery powered carbon monoxide alarm and make sure it’s fitted according to the instructions.
“The final thing is that if you have anything like that, make sure you get them serviced every year and get it done by someone qualified.
“You can’t see carbon monoxide and you can’t smell it, so unless you’ve got a detector you won’t know about it.”