Magen David Adom urged people busy cleaning for Passover to take time off and donate blood as its supplies are depleted during the holidays.
MDA began setting up blood donation spots earlier this week at tourist locations, shopping centers and other places where people congregate.
The higher accident rates during the holiday require more blood to be on hand.
Call 1-800-400-101 or (03) 530-0400, or go to www.mdais.org/dam for information about sites for blood donation; check again before going to donate, as changes may occur, MDA said on Monday.
Meanwhile, the first-aid ambulance and blood-supply organization is collecting kosher-for-Passover food to donate to the needy.
Thousands of volunteers and employees of the MDA began cooperation with the organization Orot Hahesed, which is seeking donations and is helping to paint and renovate the homes of lone elderly people.
The project will end on Sunday, when food packages will be distributed.
The food will be collected at the entrance to supermarkets and groceries between 5 and 11 p.m. on weekdays and from 9 a.m. to 1 p.m. on Friday.
Among the recommended foods are matzot, chocolate spread, long-life milk, Turkish and instant coffee, cans of tuna, potatoes, canned fruit and pickles.