Heart-shaped trivets are most commonly made from hand-braided natural jute (a natural fiber) and silicone.
Silicone heart trivets are listed with heat resistance up to 600°F (316°C). Natural jute trivets are described as protecting surfaces from hot dishes, but no specific temperature rating is provided.
Silicone heart trivets are described as very flexible, which helps with gripping and storage. Hand-braided natural jute trivets are noted as durable and have some flexibility, though they are less pliable than silicone.
Example weights for heart-shaped trivets in the available listings range from about 0.29 pounds to 0.7 pounds.
Besides protecting surfaces from heat, heart-shaped trivets can double as pot holders and jar openers, provide non-slip protection on counters, and serve as decorative tabletop accents.