Canadian Blood Services is appealing to Canadians to donate blood before heading down south and to rebook cancelled appointments.

The organization reminds Canadians travelling to tropical locales that there are new donation rules in place to protect the blood supply from Zika virus, rules that are further reducing the number of eligible donors. 

Those who have travelled to areas outside Canada, continental United States and Europe are ineligible to give blood for 21 days after their return to "mitigate the risk of the Zika virus entering the blood supply," Canadian Blood Services said in a news release.

However, the organization encourages donors to rebook an appointment after their ineligibility period has ended.

"Donated blood is needed to save lives every day. During the travel season, we count on donors to ensure an ample and safe supply of blood and blood products for those in need," Peter MacDonald, director donor relations Atlantic, said in the news release. 

The organization said this can be a difficult time of year to "maintain a strong blood supply for all Canadians," due to travel, increased rates of flu and extreme weather conditions.

"People with the flu are also asked to please re-book as soon as they can."

For more information on how you can donate, visit blood.ca or download the GiveBlood app.