An 18 and 23 year old have been taken ill at Fabric nightclub in London over the weekend.
The pair are thought to have taken ecstacy and the 23 year old from North West London is currently in critical condition.
Police warn "Users need to be aware that a potentially fatal batch of ecstasy is out there" and that if they have "purchased any ecstasy recently they should destroy it".
Reports also state that air conditioning failed during the night at the club causing drum and bass fans to overheat considerably. if the body can't cool down then many side effects are known to occur.
Whatever the reason, please party safe out there people and watch out for your friends!