Thanks for your question on Healthcare Magic.
I can understand your concern.
Yes, he can take
aspirin for headache, no harm in it.
Symptoms of
carbon monoxide poisoning are
fainting, black outs, breathlessness, Bluish discoloration of skin, nails, excessive headache,
vomiting etc.
So his headache is mostly due to inhalation of carbon monoxide.
No need to worry much for this headache. It will resolve by its own in 1-2 days with aspirin.
Ask him to take deep breathing of fresh air. Avoid such incidence in future.
Watch for above mentioned symptoms.
Don't worry, you will be alright.
Hope I have solved your query. I will be happy to help you further. Wishing good health to your husband. Thanks.