MERCY -- "I Have A Date" Episode 114 -- Pictured: (l-r) Alison Sweeney as Becky Sorenson, James LeGros as Dr.Dan Harris -- Photo by: Nicole Rivelli/NBC

Alison Sweeney is one busy woman. Not only is she a regular on the daytime drama, Days of Our Lives, but the actress also hosts the primetime reality show, The Biggest Loser. And tonight she guest stars as a woman receiving emergency treatment at Mercy Hospital on the breakout series, Mercy.

Her busy schedule takes some serious juggling, Sweeney tells HollywoodOutbreak.com. However, she admits it’s important to striking while the iron is hot.

Sweeney is used to being the veteran performer on the set, having spent many years on Days, but being the new kid on the block in an established series was more fun than she expected – plus she got to plant a hefty lip-lock on series star, James LeGros.

Click onto four media bars for:

Why Alison Sweeney said yes to Mercy.

Alison Sweeney explaining her character on Mercy.

The differences between being a veteran as opposed to guest starring on a TV show.

How Alison Sweeney balances her workload.

Mercy airs 8:00 p.m. ET/PT on NBC.