If you shop at Sears Holdings' (NASDAQOTH:SHLDQ) Sears stores, you should know that it's a risky proposition. The company has already filed for bankruptcy protection, and while it hopes to survive as a smaller company, there's no guarantee that the holiday season won't be the end for the iconic retailer.

That makes shopping at a Sears both a risk and an opportunity. You might find some great deals, but you also want to be very careful. The chain has already made the closure plans for certain individual stores (Sears and Kmart) public, and while those locations may not have "going out of business" signs up, the holidays will essentially be liquidation sales.

The following are items you should probably not buy at a Sears because the company's precarious financial situation means they might soon be worthless or without the option of return. (If you do plan to shop at a Sears or Kmart, check out our rundown of what they're doing for Black Friday.)

The exterior of a Sears store

Sears may not survive the holiday season. Image source: Sears.

1. Sears gift cards

When a company decides to liquidate -- which Sears Holdings has not done yet -- it does not always accept gift cards. It depends how the sale is managed. Even if a store near you does accepts gift cards, in the event of a liquidation, your selection will be limited. Don't spend money on something that could become useless, or at least less useful, quickly.

2. Beds/mattresses 

In general, when you buy a mattress, you have a period to exchange it if it's not comfortable. That's hard to do if the company you bought it from goes out of business, though. You don't want to be stuck with an uncomfortable bed because the retailer you bought it from went out of business.

3. Craftsman Tools

Sears sold the Craftsman brand to Stanley Black & Decker earlier this year, and while it still sells the tool line, it's no longer the best place to buy them. This one-time exclusive-to-Sears brand is now being sold at Lowe's and on Amazon. You're better off buying from either one in the event you need to make a return.

4. Clothes for someone else

You should only buy clothing at Sears if you can try it on, know it fits, and know that you like it. That's generally not how gift-giving works, and you don't want to buy something a person can't exchange or return.

Be very wary

If you buy anything from Sears, you should do so knowing that you may not be able to return or exchange it. Even if the chain survives, remember that your store could go out of business, making it more difficult to bring something back.

Sears will likely have some great prices, and if you know what you want that could be very good for your holiday budget. Just be careful, because the company has a very limited chance for long-term survival.

John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Daniel B. Kline has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Amazon. The Motley Fool recommends Lowe's. The Motley Fool has a disclosure policy.