A long hedge is used by those who suffer losses with an increase in value and want to establish the purchase price of some asset to be carried out later.
This may be the case of an importer who arranges to purchase computers from the United States in March and makes the payment upon receipt of the shipment, set for June. With the import operation, he gained exposure to the rise of the dollar, and consequently should take a position that yields benefits tied to every increase in the value of the currency, neutralizing the risk assumed.
In March, the importer bought a June futures contract at $3.05/U$S. In June, the dollar rose to $3.10/U$S. Therefore, the loss incurred by the importer when buying dollars at the spot market price is offset by the profit made on the futures market.
If the dollar had fallen to $3.00/U$S, the loss in the futures market would have been offset by the difference in his gain in the spot market. In the same way as in the short hedge, if the importer had not executed the transaction in the futures market, he would have gotten a more favorable exchange rate with the declining dollar, but he chose to make a hedge aga against a rise in prices.