Regular portal cooldown of 5 minutes in effect.
Cooldown is the time between individual hacks of a Portal. The time elapsed will depend on the Portal's alignment, the Agent's alignment, and how many 
Heat Sinks are installed on the Portal.
The standard cooldown for any given Portal is five minutes (300 seconds). This will become three minutes (180 seconds) if the Portal matches the Agent's alignment (e.g., hacking a Resistance Portal as a Resistance Agent). This can be further decreased with the use of Heat Sinks.
Cooldown is never shared between Agents. If one hacks, only they have to wait for cooldown to pass. Any and all other Agents can hack during that time.
When hacking during the cooldown period, the following message is displayed: "Portal running hot! Cooldown in ... seconds."