The American Red Cross is urging blood and platelet donors to make appointments now as hospitals work to maintain a reliable blood supply during the busy summer season.

Red Cross officials say the need for blood does not take a vacation, even as many families prepare for summer travel, holiday gatherings, and Independence Day celebrations. Summer schedules, severe weather, and fewer scheduled donations can all affect the availability of lifesaving blood products.

To encourage donations, the Red Cross is partnering with Warner Bros. Discovery Global Consumer Products for a special Looney Tunes-themed promotion. Everyone who comes to give blood between June 29 and July 12 will receive a classic Red Cross x Looney Tunes T-shirt, while supplies last.

All blood types are needed. Donors can schedule an appointment by visiting RedCrossBlood.org, using the Red Cross Blood Donor App, or calling 1-800-RED CROSS.

Eligible donors must generally be in good health, weigh at least 110 pounds, and meet age requirements. Donors are also reminded that they can save time by completing RapidPass online on the day of their donation before arriving at the blood drive.

The American Red Cross supplies about 40 percent of the nation’s blood and depends on donors, volunteers, and public support to carry out its mission.