WLANs that are installed at airports, hotels, and other establishments present high security risks. Typically, you would disable any wireless encryption or access control on your laptop before connecting to a public LAN. Thus, any information you exchange is sent unencrypted, and furthermore your laptop may be subject to probes and scanning from other clients connected to the LAN. Therefore, the following recommendations should be followed:
Do not use a public LAN with your work- related laptop unless it is absolutely necessary.
Use a VPN, because otherwise all messages can be intercepted.
Use a personal firewall and ensure that its settings are set at maximum protection.
Upon leaving the LAN, immediately restore all security settings.
Scan the laptop for viruses and spyware.